Chapter 18 · 6 hours

Hydrocarbon and its Compounds

SEE past exam questions

Past questions and answers

59 questions set from this chapter, 5 of them more than once. Most repeated first.

Asked 2 times
2081 Chaitra · Koshi · 1 mark
2082 Chaitra · Sudurpashchim · 1 mark

Write the structural formula of glycerol.

Answer

Glycerol is propane-1,2,3-triol, $C_3H_5(OH)_3$ or $CH_2OH-CHOH-CH_2OH$ .

      H   H   H
      |   |   |
  H - C - C - C - H
      |   |   |
      OH  OH  OH

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

Asked 2 times
2080 Chaitra · Koshi · 2 marks
2081 Chaitra · Lumbini · 2 marks

Write the IUPAC name and structural formula of the compound formed by replacing one hydrogen atom of each carbon atom of ethane by an -OH group.

Answer

Ethane is $CH_3-CH_3$ . Replacing one H of each carbon by -OH gives $HO-CH_2-CH_2-OH$ .

IUPAC name: ethane-1,2-diol (common name: ethylene glycol or glycol).

Structural formula:

      H   H
      |   |
  HO- C - C -OH
      |   |
      H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

Asked 2 times
2082 Asar · Grade increment · 1 mark
2082 Chaitra · Gandaki · 1 mark

Which one is the general molecular formula of alkene?
(a) $C_nH_{2n-2}$ (b) $C_nH_{2n}$ (c) $C_nH_{2n+1}$ (d) $C_nH_{2n+2}$

Answer

(b) $C_nH_{2n}$ . Alkenes contain one carbon-carbon double bond, so they have two fewer hydrogen atoms than alkanes ( $C_nH_{2n+2}$ ), e.g. ethene $C_2H_4$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

Asked 2 times
2081 Chaitra · Lumbini · 1 mark
2079 Chaitra · Bagmati · 1 mark

Write the IUPAC name of the given structural formula (CH3-CH2-OH).

Answer

The IUPAC name of $CH_3-CH_2-OH$ is ethanol (two carbons, alcohol group -OH).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

Asked 2 times
2082 Chaitra · Koshi · 2 marks
2079 Chaitra · Koshi · 2 marks

Study the structure of the given organic compound (CH3-CH2-OH).
(a) Write the general molecular formula of the compound.
(b) In which group of organic compounds does this compound belong?

Answer

(a) The general molecular formula of the compound is $C_nH_{2n+1}OH$ (here $n=2$ , $C_2H_5OH$ ).

(b) It belongs to the group of alcohols (alkanols), with the functional group -OH.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Lumbini · 1 mark

Which of the following is a tri-hydric alcohol?
(a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

Similar questions: Di-hydric alcohol (2081 Chaitra · Bagmati)

Answer

(d) Glycerol. It has three -OH groups ( $C_3H_5(OH)_3$ ), so it is tri-hydric. Ethanol and methanol have one -OH, ethylene glycol has two.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2081 Chaitra · Bagmati · 1 mark

Which of the following is a di-hydric alcohol?
(a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

Similar questions: Tri-hydric alcohol (2080 Chaitra · Lumbini)

Answer

(b) Ethylene glycol. Its formula $HOCH_2-CH_2OH$ has two -OH groups, so it is a di-hydric alcohol.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2080 Chaitra · Bagmati · 1 mark

Which suffix is present in the name of hydrocarbons with general formula $C_nH_{2n-2}$ ?
(i) -ane (ii) -ene (iii) -ol (iv) -yne

Similar questions: Suffix for CnH2n (2080 Chaitra · Sudurpashchim)

Answer

(iv) -yne. Hydrocarbons with general formula $C_nH_{2n-2}$ are alkynes, which contain a triple bond, e.g. ethyne $C_2H_2$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2080 Chaitra · Sudurpashchim · 1 mark

Which suffix is present in the name of hydrocarbons with general formula $C_nH_{2n}$ ?
(a) -ane (b) -ene (c) -ol (d) -yne

Similar questions: Suffix for CnH2n-2 (2080 Chaitra · Bagmati)

Answer

(b) -ene. Hydrocarbons with general formula $C_nH_{2n}$ are alkenes (one double bond), e.g. ethene $C_2H_4$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2082 Chaitra · Gandaki · 2 marks
CDC model paper 2080, Science and Technology · 2 marks

A colourless viscous liquid hydrocarbon is used as a sweetening agent in confectionery.
(a) Write the IUPAC name of this compound.
(b) Write the structural formula of the compound formed by replacing all -OH by H.

Answer

(a) The compound is glycerol (glycerine). Its IUPAC name is propane-1,2,3-triol, because it is a three-carbon chain (propane) with an -OH group on each carbon (a tri-hydric alcohol).

(b) Replacing all three -OH groups by H gives propane, $CH_3-CH_2-CH_3$ .

      H   H   H
      |   |   |
  H - C - C - C - H
      |   |   |
      H   H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 1, Science and Technology · 2 marks
2081 Chaitra · Madhesh · 2 marks

Write the name of the member of alkyne which contains an equal number of hydrogen and carbon. Write its structural formula / one use of it.

Answer

The alkyne with equal numbers of hydrogen and carbon atoms is ethyne (acetylene), $C_2H_2$ , since $C_nH_{2n-2}$ with $n=2$ gives 2 C and 2 H.

Structural formula: $H-C\equiv C-H$

Use: it is burnt with oxygen in the oxy-acetylene flame to weld and cut metals.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Madhesh · 1 mark

Write an application of the given hydrocarbon in daily life.
Figure: Structural formula of propane-1,2,3-triol (glycerol): a chain of three carbon atoms, H-C-C-C-H, each carbon bearing one OH group on top and one H below.

Answer

The given compound is glycerol (propane-1,2,3-triol). One use: it is used as a sweetening agent in confectionery and to make soap, cosmetics and nitroglycerine (explosives).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Grade increment · 1 mark

Which of the following is the correct molecular formula for the given structural formula (three carbons in a chain, each bearing one -OH)?
(a) C $_3$ H $_6$ (OH) $_2$ (b) C $_3$ H $_5$ (OH) $_3$ (c) C $_3$ H $_4$ (H.OH) $_3$ (d) C $_3$ H $_2$ (OH $_2$ ) $_3$
Figure: Structural formula of three carbon atoms in a chain, H-C-C-C-H, each carbon bonded to one H above and one OH below; the end carbons also carry an H on the outer side.

Answer

(b) $C_3H_5(OH)_3$ . The structure has three carbons, each with one -OH. The chain carbons carry 2+1+2 = 5 hydrogens apart from the three OH groups, so the formula is $C_3H_5(OH)_3$ (glycerol).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2081 Shrawan · Grade increment · 2 marks

Write the IUPAC name of the given compound (ethane). Write a use of the compound which is formed by replacing one hydrogen atom from each carbon by an -OH group.
Figure: Structural formula of ethane: two carbon atoms joined by a single bond, each carbon bonded to three hydrogen atoms (H3C-CH3).

Answer

Name: the given compound, $CH_3-CH_3$ (two carbons, single bond), is ethane.

Use: replacing one H on each carbon by -OH gives ethane-1,2-diol (ethylene glycol), which is used as antifreeze in car radiators (it lowers the freezing point of water).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Madhesh · 2 marks

A saturated hydrocarbon has its molecular mass 30 amu. Write the IUPAC name of the compound formed by replacing two -H atoms, one from each carbon atom, by one -OH group each. Also write one use of that compound.

Answer

Alkane $C_nH_{2n+2}$ : $12n+2n+2=30$ , so $14n=28$ , $n=2$ . The hydrocarbon is ethane, $C_2H_6$ .

Replacing one H of each carbon by -OH gives $HO-CH_2-CH_2-OH$ , named ethane-1,2-diol.

Use: as antifreeze in vehicle radiators.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Karnali · 2 marks

Write the name and structural formula of the alcohol having two carbons.

Answer

The alcohol with two carbons is ethanol (ethyl alcohol), $C_2H_5OH$ .

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Gandaki · 1 mark

Write a use of the organic compound given in the figure (ethanol).

Answer

Ethanol is used as a thermometric liquid, as a disinfectant for wounds and syringes, as a solvent for paints and perfumes, and as a fuel (mixed with petrol).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Sudurpashchim · 2 marks

A homologous series of alcohol is given in the table. In serial no. 2, 'X' is written instead of the real compound.

SN Homologous series
1. $CH_3OH$
2. X
3. $CH_3CH_2CH_2OH$
a. Write the molecular formula of X.
b. Write the structural formula of the compound formed by the removal of one H and one -OH from the compound kept at X.
Figure: Table of a homologous series of alcohols: 1. CH3OH, 2. X, 3. CH3CH2CH2OH.

SN	Homologous series
1.	$CH_3OH$
2.	X
3.	$CH_3CH_2CH_2OH$

Answer

a. The series increases by $-CH_2-$ each time: methanol, ethanol, propanol. X is ethanol, molecular formula $C_2H_5OH$ ( $C_2H_6O$ ).

b. Removing H from one carbon and -OH from the adjacent carbon of $CH_3CH_2OH$ gives ethene (a double bond forms):

  H     H
   \   /
    C=C
   /   \
  H     H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Karnali · 1 mark

Which compound is formed when one hydrogen of ethane is replaced by a hydroxide group?
(a) Ethane (b) Ethyne (c) Ethanol (d) Ethene

Answer

(c) Ethanol. Replacing one H of ethane ( $C_2H_6$ ) by -OH gives $C_2H_5OH$ , which is ethanol.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2082 Asar · Grade increment · 2 marks

Structural formulas of two compounds are given: (A) CH $_2$ =CH-CH $_3$ and (B) CH $_3$ -CH $_2$ -OH.
(a) Which one compound is an unsaturated hydrocarbon?
(b) Which compound can be used in a thermometer?
Figure: (A) is CH2=CH-CH3 drawn structurally (propene); (B) is CH3-CH2-OH drawn structurally (ethanol).

Answer

(a) Compound A, $CH_2=CH-CH_3$ (propene), is unsaturated because it has a carbon-carbon double bond.

(b) Compound B, $CH_3-CH_2-OH$ (ethanol), is used in thermometers because it stays liquid at very low temperatures (freezing point about -114 C).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Sudurpashchim · 2 marks

A student made a model of methane and another student made a model of propane. Their teacher removed one hydrogen atom from the terminal of each model and joined them together. Which hydrocarbon is formed? Write its structural formula too.

Answer

Methane $CH_4$ minus one H gives $CH_3-$ . Propane $CH_3CH_2CH_3$ minus one terminal H gives $CH_3CH_2CH_2-$ . Joining them forms a four-carbon chain, butane ( $C_4H_{10}$ ).

Structural formula:

      H   H   H   H
      |   |   |   |
  H - C - C - C - C - H
      |   |   |   |
      H   H   H   H

or $CH_3-CH_2-CH_2-CH_3$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Sudurpashchim · 2 marks

Write the structural formula of marsh gas. Write the IUPAC name of the compound formed when one 'H' of the hydrocarbon is replaced by one 'OH'.

Answer

Marsh gas is methane, $CH_4$ .

      H
      |
  H - C - H
      |
      H

Replacing one H by -OH gives $CH_3OH$ , whose IUPAC name is methanol.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Bagmati · 2 marks

A homologous series of alkane is given in the table but in serial no. 4, 'X' is given instead of the real compound.

S.N. Homologous series
1. $CH_4$
2. $CH_3CH_3$
3. $CH_3CH_2CH_3$
4. X
i. Write the molecular formula of X.
ii. Write the structural formula of the compound formed by the removal of one H atom from the two carbons of one end.

S.N.	Homologous series
1.	$CH_4$
2.	$CH_3CH_3$
3.	$CH_3CH_2CH_3$
4.	X

Answer

i. The alkane series increases by $CH_2$ each member, so X (4th member) is butane, molecular formula $C_4H_{10}$ .

ii. Removing one H from each of the two carbons at one end of butane ( $CH_3-CH_2-CH_2-CH_3$ ) forms a double bond between them, giving but-1-ene:

  H     H
   \   /
    C=C - CH2 - CH3
   /
  H

i.e. $CH_2=CH-CH_2-CH_3$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Karnali · 2 marks

A homologous series of a type of hydrocarbon is given in the table. X and Y are given in serial numbers 2 and 3 instead of the real compounds.

S.N. Homologous series
1. CH $_4$
2. X
3. Y
4. CH $_3$ CH $_2$ CH $_2$ CH $_3$
i. Write the molecular structure of the compound formed when one hydrogen atom of X is displaced by -OH. ii. Write the structural formula of the compound formed by the removal of one hydrogen atom from two adjacent carbon atoms of Y.
Figure: Table of a homologous series with CH4, X, Y, CH3CH2CH2CH3 in rows 1-4.

S.N.	Homologous series
1.	CH $_4$
2.	X
3.	Y
4.	CH $_3$ CH $_2$ CH $_2$ CH $_3$

Answer

The series is the alkanes: methane, X = ethane ( $CH_3CH_3$ ), Y = propane ( $CH_3CH_2CH_3$ ), butane.

i. Replacing one H of ethane by -OH gives ethanol: $CH_3-CH_2-OH$ .

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

ii. Removing one H from two adjacent carbons of propane gives propene (double bond):

$CH_2=CH-CH_3$

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Bagmati · 4 marks

(a) What is meant by homologous series of hydrocarbon? (b) An example of homologous series of hydrocarbon is given in the table:

Compound Homologous series
A CH $_3$ -CH $_3$
B CH $_3$ -CH $_2$ -CH $_3$
C CH $_3$ -CH $_2$ -CH $_2$ -CH $_3$
(i) Write the IUPAC name of the compound 'B'. (ii) Write the structural formula of the compound formed when one hydrogen atom of compound 'A' is displaced by '-OH'. (iii) Write the general molecular formula of the compound formed when one hydrogen atom from each of two middle carbon atoms is removed from compound 'C'.

Compound	Homologous series
A	CH $_3$ -CH $_3$
B	CH $_3$ -CH $_2$ -CH $_3$
C	CH $_3$ -CH $_2$ -CH $_2$ -CH $_3$

Answer

(a) A homologous series of hydrocarbons is a group of hydrocarbons with the same general formula and similar chemical properties, in which successive members differ by a $-CH_2-$ group (14 amu), e.g. ethane, propane, butane.

(b)(i) Compound B is $CH_3CH_2CH_3$ , propane.

(ii) A is ethane. Replacing one H by -OH gives ethanol:

$CH_3-CH_2-OH$

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

(iii) C is butane. Removing one H from each of the two middle carbons gives $CH_3-CH=CH-CH_3$ (but-2-ene), an alkene, with general molecular formula $C_nH_{2n}$ (here $C_4H_8$ ).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Bagmati · 2 marks

Write the structural formula of the saturated hydrocarbon having molecular mass 44 amu. Write the IUPAC name of the compound which is obtained by removing two hydrogen atoms from adjacent carbons.

Answer

Alkane $C_nH_{2n+2}$ : $12n+2n+2=44$ , so $14n=42$ , $n=3$ . It is propane, $C_3H_8$ .

      H   H   H
      |   |   |
  H - C - C - C - H
      |   |   |
      H   H   H

Removing two H atoms from adjacent carbons gives $CH_2=CH-CH_3$ , named propene.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Koshi · 1 mark

A saturated hydrocarbon has a molecular mass of 58 amu. Write its IUPAC name.

Answer

$C_nH_{2n+2}$ : $14n+2=58$ , so $n=4$ . The compound is $C_4H_{10}$ , butane.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2080 Chaitra · Lumbini · 2 marks

Which compound is formed by removing two hydrogen atoms from a saturated hydrocarbon with two carbons? Mention one application of the compound formed by adding one hydrogen atom to one carbon and one hydroxyl group to the other carbon.

Answer

Ethane $C_2H_6$ minus two hydrogen atoms (one from each carbon) gives ethene, $CH_2=CH_2$ ( $C_2H_4$ ).

Adding H to one carbon and -OH to the other (across the double bond) gives ethanol, $CH_3CH_2OH$ . Use: ethanol is used as a solvent, a fuel additive, a disinfectant and in thermometers.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Madhesh · 4 marks

The commonly used gas for cooking is LPG. Two compounds present in LPG are saturated hydrocarbons, one of them containing 3 carbons and the other 4 carbons.
(i) Write the molecular formulas of these compounds.
(ii) What makes these gases exist in liquid state in the gas cylinder?
(iii) Write the balanced chemical equation of the reaction involved when the hydrocarbon having 3 carbon atoms burns with oxygen.

Answer

(i) The 3-carbon compound is propane, $C_3H_8$ ; the 4-carbon compound is butane, $C_4H_{10}$ .

(ii) LPG is stored under high pressure (and is easily liquefied by compression), which keeps the gases in the liquid state inside the cylinder.

(iii) Propane burns completely in oxygen:

C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O + \text{heat}

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Gandaki · 2 marks

On the basis of the information given in the table, write the structural formula of A and B.

Compounds Bond Carbon number Functional group
A Triple 2
B Single 3 Alcohol
Figure: Table: compound A has a triple bond, 2 carbons, functional group column blank/illegible; compound B has a single bond, 3 carbons, alcohol functional group.

Compounds	Bond	Carbon number	Functional group
A	Triple	2
B	Single	3	Alcohol

Answer

A: two carbons joined by a triple bond is ethyne (alkyne), $H-C\equiv C-H$ ( $C_2H_2$ ).

B: three carbons with only single bonds and an alcohol group (-OH) is propanol (propan-1-ol), $CH_3-CH_2-CH_2-OH$ .

      H   H   H
      |   |   |
  H - C - C - C - OH
      |   |   |
      H   H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Koshi · 2 marks

Write the general molecular formula of the compound given ( $H-C\equiv C-H$ ). Also write the IUPAC name of the compound.
Figure: Structural formula of a compound: H-C≡C-H (ethyne/acetylene).

Answer

The general molecular formula of the alkyne series is $C_nH_{2n-2}$ . The compound $H-C\equiv C-H$ is ethyne (acetylene), $C_2H_2$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Chaitra · Gandaki · 1 mark

An organic compound is made up of two carbon atoms and two hydrogen atoms with general formula $C_nH_{2n-2}$ . Identify the compound.
(a) Ethane (b) Ethene (c) Ethyl (d) Ethyne

Answer

(d) Ethyne. For $n=2$ , $C_nH_{2n-2}$ gives $C_2H_2$ ; it has a triple bond. Ethane is $C_2H_6$ and ethene is $C_2H_4$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2081 Chaitra · Gandaki · 1 mark

Write a general molecular formula of alkyne.

Answer

The general molecular formula of alkynes is $C_nH_{2n-2}$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Lumbini · 1 mark

Which of the following is the alkyne having 5 carbon atoms?
(a) pentane (b) Pentene (c) Pentyne (d) Pentyl

Answer

(c) Pentyne. The suffix -yne marks an alkyne (triple bond) and 'pent' means 5 carbons: $C_5H_8$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2081 Chaitra · Karnali · 1 mark

Which of the following hydrocarbon groups belongs to alkyne?

(A)  H-C≡C-H
(B)  H2C=CH2
(C)  H3C-CH3
(D)  H3C-C≡C-CH3

(a) A and C (b) A and B (c) A and D (d) B and C
Figure: Four structural formulas: (A) H-C≡C-H; (B) H2C=CH2; (C) H3C-CH3 drawn fully; (D) H3C-C≡C-CH3 drawn fully.

Answer

(c) A and D. An alkyne has a carbon-carbon triple bond: (A) $H-C\equiv C-H$ is ethyne and (D) $H_3C-C\equiv C-CH_3$ is butyne. (B) is ethene (double bond) and (C) is ethane (single bond).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2081 Shrawan · Grade increment · 1 mark

Write the structural formula of the unsaturated hydrocarbon having two carbon atoms with a double bond.

Answer

The unsaturated hydrocarbon with two carbons and a double bond is ethene, $CH_2=CH_2$ :

  H     H
   \   /
    C=C
   /   \
  H     H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Madhesh · 1 mark

Write the IUPAC name of the given compound (CH $_2$ =CH-CH $_3$ ).

Answer

The IUPAC name of $CH_2=CH-CH_3$ is propene.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Karnali · 1 mark

Which of the following is correct about saturated hydrocarbon?
(a) carbon-carbon has four bonds and general formula $C_nH_{2n+2}$ (b) carbon-carbon has double or triple bond and general formula $C_nH_{2n}$ (c) carbon-carbon has single bond and general formula $C_nH_{2n+2}$ (d) carbon-carbon has single and double bond and general formula $C_nH_{2n-2}$

Answer

(c) Carbon-carbon has single bond and general formula $C_nH_{2n+2}$ . Saturated hydrocarbons (alkanes) contain only single bonds between carbon atoms, e.g. methane $CH_4$ , ethane $C_2H_6$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 1 MCQ

Loading…

2082 Chaitra · Karnali · 2 marks

Complete the given M-chart.

Hydrocarbon Bond Chemical Nature Additional name
saturated single covalent Y paraffins
unsaturated X unstable and more reactive olefins
Figure: M-chart table with blanks X (bond of unsaturated hydrocarbon) and Y (chemical nature of saturated hydrocarbon).

Hydrocarbon	Bond	Chemical Nature	Additional name
saturated	single covalent	Y	paraffins
unsaturated	X	unstable and more reactive	olefins

Answer

X: double or triple covalent bond (unsaturated hydrocarbons have a double bond in alkenes or a triple bond in alkynes).

Y: stable and less reactive (saturated hydrocarbons).

Hydrocarbon	Bond	Chemical Nature	Additional name
saturated	single covalent	stable and less reactive	paraffins
unsaturated	double or triple covalent	unstable and more reactive	olefins

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2082 Chaitra · Lumbini · 2 marks

Write difference between alkane and alkyne on the basis of number of bonds and general molecular formula.

Answer

Basis	Alkane	Alkyne
Bonds between carbons	Only single bonds ( $C-C$ )	One triple bond ( $C\equiv C$ )
General molecular formula	$C_nH_{2n+2}$	$C_nH_{2n-2}$

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Gandaki · 1 mark

Write a difference between ethane and ethene.

Answer

Ethane ( $C_2H_6$ ) is saturated, with a single C-C bond, while ethene ( $C_2H_4$ ) is unsaturated, with a C=C double bond.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2081 Chaitra · Sudurpashchim · 1 mark

Why are hydrocarbons called organic compounds?

Answer

Hydrocarbons are called organic compounds because they are made of carbon and hydrogen and are obtained from living things and their remains (e.g. petroleum, natural gas, derived from plants and animals).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2080 Grade increment · 2 marks

Study the given bar diagram. Write the molecular structure and IUPAC name of the compound formed from the atoms of the elements of atomic mass given in the bar diagram.
Figure: Bar graph with three bars: Mass of Carbon = 24, Mass of Hydrogen = 6, Mass of Oxygen = 16.

Answer

Number of atoms = mass / atomic mass: carbon $24/12=2$ , hydrogen $6/1=6$ , oxygen $16/16=1$ .

Molecular formula: $C_2H_6O$ , which with the -OH group is $C_2H_5OH$ .

IUPAC name: ethanol.

Molecular structure:

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Madhesh · 1 mark

What is the name of the group of hydrocarbons with the general formula $C_nH_{2n}$ ?

Answer

Alkenes (unsaturated hydrocarbons with a carbon-carbon double bond).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Gandaki · 1 mark

Write the name of an alkane having three carbon atoms.

Answer

The alkane with three carbon atoms is propane ( $C_3H_8$ ).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Karnali · 1 mark

What is a hydrocarbon?

Answer

A hydrocarbon is an organic compound made up of only carbon and hydrogen atoms, for example methane ( $CH_4$ ) and ethene ( $C_2H_4$ ).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Sudurpashchim · 1 mark

Define functional group.

Answer

A functional group is an atom or group of atoms present in an organic compound that decides its characteristic chemical properties. For example, $-OH$ in alcohols and $-COOH$ in carboxylic acids.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Bagmati · 2 marks

Structural formulae of some compounds are given below. (A) $H_3C-CH_3$ drawn in full structural form (B) $H_2C=CH_2$ drawn in full structural form (C) glycerol, $HOCH_2-CHOH-CH_2OH$ drawn in full structural form
(a) Which one of them is an unsaturated hydrocarbon? (b) Write any one use of 'C'.
OR
(a) Give an example of an unsaturated hydrocarbon. (b) Write an use of glycerine.

Answer

(a) Compound B ( $H_2C=CH_2$ , ethene) is the unsaturated hydrocarbon, because it has a carbon-carbon double bond.

(b) Compound C is glycerol (glycerine). It is used in making soaps, cosmetics and explosives such as nitroglycerine (dynamite).

(a) Ethene ( $C_2H_4$ ) (or ethyne, $C_2H_2$ ) is an unsaturated hydrocarbon.

(b) Glycerine is used in making cosmetics, soaps and medicines (also as a moisturiser in lotions).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Gandaki · 2 marks

Write any two differences between homologous series and functional group.

Answer

Homologous series	Functional group
A series of organic compounds with the same functional group and similar chemical properties, in which successive members differ by a $-CH_2-$ group.	An atom or group of atoms that decides the chemical properties of an organic compound.
It is a whole family of compounds, e.g. $CH_3OH$ , $C_2H_5OH$ , $C_3H_7OH$ (alcohols).	It is only a part of a molecule, e.g. $-OH$ in all of these alcohols.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Karnali · 2 marks

Write any two differences between saturated and unsaturated hydrocarbons.

Answer

Saturated hydrocarbons	Unsaturated hydrocarbons
Contain only single bonds between carbon atoms (e.g. ethane, $C_2H_6$ ).	Contain at least one double or triple bond between carbon atoms (e.g. ethene, ethyne).
Less reactive; they undergo substitution reactions.	More reactive; they undergo addition reactions.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Sudurpashchim · 2 marks

Write the structural formula of the following compounds. (a) $C_3H_8O_3$ , trihydric alcohol (glycerol) (b) $C_2H_2$ , hydrocarbon
OR
Write any two differences between ethene and ethyne.

Answer

(a) Glycerol, $C_3H_8O_3$ (propane-1,2,3-triol):

      H   H   H
      |   |   |
  H - C - C - C - H
      |   |   |
      O   O   O
      |   |   |
      H   H   H

(b) Ethyne, $C_2H_2$ :

  H - C ≡ C - H

Ethene	Ethyne
Molecular formula $C_2H_4$ ; has a carbon-carbon double bond.	Molecular formula $C_2H_2$ ; has a carbon-carbon triple bond.
Burns with a sooty (slightly smoky) flame; used to ripen fruits.	Burns with a very hot, sooty flame; used in gas welding and cutting of metals.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Madhesh · 3 marks

A saturated hydrocarbon is formed by the hydrogenation of an alkene having 2 carbon atoms and general formula $C_nH_{2n}$ . One of the reactants in the given reaction when burnt in air produces a gas which turns lime water milky. (a) Write the IUPAC names of the reactant and product as described in the first statement. (b) Write the balanced equation of the reaction occurring in the first statement. (c) Write the name of the milky compound formed as described in the second statement.

Answer

(a) The alkene with 2 carbon atoms is ethene ( $C_2H_4$ ), which is the reactant. The saturated hydrocarbon formed is ethane ( $C_2H_6$ ), which is the product. (The IUPAC names are ethene and ethane.)

(b) Hydrogenation of ethene (nickel catalyst, heat):

$C_2H_4 + H_2 \xrightarrow{Ni} C_2H_6$

(c) Ethene burns in air to give carbon dioxide, which turns lime water milky by forming insoluble calcium carbonate ( $CaCO_3$ ):

$Ca(OH)_2 + CO_2 \to CaCO_3 + H_2O$

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

2079 Chaitra · Lumbini · 3 marks

An organic compound has the elements C, H and O in it. It is used in thermometers. (a) Identify it and write its functional group. (b) Write its IUPAC name. (c) Write the name of the traditional method of preparation of this compound.

Answer

(a) The compound is ethyl alcohol (ethanol), $C_2H_5OH$ . Its functional group is the hydroxyl group, $-OH$ . (It is used in thermometers because it has a low freezing point and expands evenly.)

(b) Its IUPAC name is ethanol.

(c) The traditional method of preparing it is fermentation: sugary substances such as molasses (sugarcane juice) or grains are fermented by yeast, whose enzymes convert the sugar into ethanol and carbon dioxide.

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 2, Science and Technology · 2 marks

A hydrocarbon compound 'A' is used to preserve biological specimen and next hydrocarbon 'B' is used as sweetening agent in confectionery.
(i) Write down the IUPAC name of compound 'A'.
(ii) Write the structural formula of compound 'B'.

Answer

(i) Compound A is formalin, a 40% solution of formaldehyde, used to preserve biological specimens. Its IUPAC name is methanal ( $HCHO$ ).

(ii) Compound B is glycerol (propane-1,2,3-triol), the sweetening agent used in confectionery.

      H   H   H
      |   |   |
  H - C - C - C - H
      |   |   |
      OH  OH  OH

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 1, Science and Technology · 1 mark

Write the structural formula of glycol.

Answer

Glycol is ethane-1,2-diol, $HO-CH_2-CH_2-OH$ .

      H   H
      |   |
  HO- C - C -OH
      |   |
      H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 3, Science and Technology · 1 mark

Write the structural formula of ethanol.

Answer

Ethanol, $CH_3CH_2OH$ :

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 3, Science and Technology · 2 marks

A monohydric alcohol is used as thermometric liquid and as disinfectant in syringe and wounds.
(a) Write the structural formula of that alcohol.
(b) Write the molecular formula of the fourth member of the alcohol homologous series in which the given alcohol lies.

Answer

(a) The alcohol is ethanol, $CH_3CH_2OH$ .

      H   H
      |   |
  H - C - C - OH
      |   |
      H   H

(b) The alcohol series is methanol ( $CH_3OH$ ), ethanol ( $C_2H_5OH$ ), propanol ( $C_3H_7OH$ ), butanol. The fourth member is butanol, molecular formula $C_4H_9OH$ ( $C_4H_{10}O$ ).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

SEE 2080 model question, Set 2, Science and Technology · 1 mark

Write the molecular formula of the given compound (CH $_2$ =CH-CH $_3$ ).

Answer

The molecular formula of $CH_2=CH-CH_3$ is $C_3H_6$ .

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

CDC model paper 2080, Science and Technology · 1 mark

Write a difference between the given hydrocarbons (Fig A: ethane H $_3$ C-CH $_3$ ; Fig B: ethene H $_2$ C=CH $_2$ ) on the basis of reactivity.
Figure: Fig A: structural formula of ethane, H3C-CH3 (each carbon with three H, single C-C bond). Fig B: structural formula of ethene, H2C=CH2 (double bond between the two carbons).

Answer

Ethane (Fig A) has only a single bond, so it is stable and less reactive. Ethene (Fig B) has a double bond, so it is unstable and more reactive (it easily undergoes addition reactions).

Answer checked by Claude Sonnet · Oct 21, 2026

Test yourself · 2 MCQs

Loading…

Questions from SEE 2082 Science and Technology, 1041 Koshi (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Madhesh (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Bagmati (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Gandaki (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Lumbini (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Karnali (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Sudurpashchim (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2081 Science and Technology, 1041 Koshi (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Madhesh (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Bagmati (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Gandaki (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Lumbini (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Karnali (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Sudurpashchim (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2080 Science and Technology, 1041 Koshi (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Madhesh (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Bagmati (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Gandaki (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Lumbini (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Karnali (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Sudurpashchim (Board exam, 2080 (scanned PDF, bilingual)), SEE 2082 Science and Technology, GI-1041 (grade increment) (Grade increment, Asar 2083 (PDF)), SEE 2081 Science and Technology, GI-1041 (grade increment) (Grade increment 2081 (8 page images); month taken from the August 2025 post, check), SEE 2080 Science and Technology, GI-1041 (grade increment) (Grade increment 2080 (PDF)), CDC model paper 2080, Science and Technology (with answer key) (Official CDC model paper, pages 2-9; answer key pages 10-15), SEE 2080 model question, Set 1, Science and Technology (Model paper Set 1 (typed PDF, publisher not named, no answers)), SEE 2080 model question, Set 2, Science and Technology (Model paper Set 2 (typed PDF, publisher not named, no answers)), SEE 2080 model question, Set 3, Science and Technology (Model paper Set 3 (typed PDF, publisher not named, no answers)), SEE 2079 Compulsory Science (RE-111) Koshi (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Madhesh (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Bagmati (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Gandaki (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Lumbini (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Karnali (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken) and SEE 2079 Compulsory Science (RE-111) Sudurpashchim (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken). Answers are written for this site; check them against your class notes.

Chapter titles and hours from the official syllabus ↗

Past questions and answers

1.Write the structural formula of glycerol.

2.Write the IUPAC name and structural formula of the compound formed by replacing one hydrogen atom of each carbon atom of ethane by an -OH group.

3.Which one is the general molecular formula of alkene? (a) CnH2n−2C_nH_{2n-2}Cn​H2n−2​ (b) CnH2nC_nH_{2n}Cn​H2n​ (c) CnH2n+1C_nH_{2n+1}Cn​H2n+1​ (d) CnH2n+2C_nH_{2n+2}Cn​H2n+2​

4.Write the IUPAC name of the given structural formula (CH3-CH2-OH).

5.Study the structure of the given organic compound (CH3-CH2-OH). (a) Write the general molecular formula of the compound. (b) In which group of organic compounds does this compound belong?

6.Which of the following is a tri-hydric alcohol? (a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

7.Which of the following is a di-hydric alcohol? (a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

8.Which suffix is present in the name of hydrocarbons with general formula CnH2n−2C_nH_{2n-2}Cn​H2n−2​? (i) -ane (ii) -ene (iii) -ol (iv) -yne

9.Which suffix is present in the name of hydrocarbons with general formula CnH2nC_nH_{2n}Cn​H2n​? (a) -ane (b) -ene (c) -ol (d) -yne

10.A colourless viscous liquid hydrocarbon is used as a sweetening agent in confectionery. (a) Write the IUPAC name of this compound. (b) Write the structural formula of the compound formed by replacing all -OH by H.

11.Write the name of the member of alkyne which contains an equal number of hydrogen and carbon. Write its structural formula / one use of it.

12.Write an application of the given hydrocarbon in daily life. Figure: Structural formula of propane-1,2,3-triol (glycerol): a chain of three carbon atoms, H-C-C-C-H, each carbon bearing one OH group on top and one H below.

14.Write the IUPAC name of the given compound (ethane). Write a use of the compound which is formed by replacing one hydrogen atom from each carbon by an -OH group. Figure: Structural formula of ethane: two carbon atoms joined by a single bond, each carbon bonded to three hydrogen atoms (H3C-CH3).

15.A saturated hydrocarbon has its molecular mass 30 amu. Write the IUPAC name of the compound formed by replacing two -H atoms, one from each carbon atom, by one -OH group each. Also write one use of that compound.

16.Write the name and structural formula of the alcohol having two carbons.

17.Write a use of the organic compound given in the figure (ethanol).

19.Which compound is formed when one hydrogen of ethane is replaced by a hydroxide group? (a) Ethane (b) Ethyne (c) Ethanol (d) Ethene

21.A student made a model of methane and another student made a model of propane. Their teacher removed one hydrogen atom from the terminal of each model and joined them together. Which hydrocarbon is formed? Write its structural formula too.

22.Write the structural formula of marsh gas. Write the IUPAC name of the compound formed when one 'H' of the hydrocarbon is replaced by one 'OH'.

26.Write the structural formula of the saturated hydrocarbon having molecular mass 44 amu. Write the IUPAC name of the compound which is obtained by removing two hydrogen atoms from adjacent carbons.

27.A saturated hydrocarbon has a molecular mass of 58 amu. Write its IUPAC name.

28.Which compound is formed by removing two hydrogen atoms from a saturated hydrocarbon with two carbons? Mention one application of the compound formed by adding one hydrogen atom to one carbon and one hydroxyl group to the other carbon.

31.Write the general molecular formula of the compound given (H−C≡C−HH-C\equiv C-HH−C≡C−H). Also write the IUPAC name of the compound. Figure: Structural formula of a compound: H-C≡C-H (ethyne/acetylene).

32.An organic compound is made up of two carbon atoms and two hydrogen atoms with general formula CnH2n−2C_nH_{2n-2}Cn​H2n−2​. Identify the compound. (a) Ethane (b) Ethene (c) Ethyl (d) Ethyne

33.Write a general molecular formula of alkyne.

34.Which of the following is the alkyne having 5 carbon atoms? (a) pentane (b) Pentene (c) Pentyne (d) Pentyl

35.Which of the following hydrocarbon groups belongs to alkyne? (A) H-C≡C-H (B) H2C=CH2 (C) H3C-CH3 (D) H3C-C≡C-CH3 (a) A and C (b) A and B (c) A and D (d) B and C Figure: Four structural formulas: (A) H-C≡C-H; (B) H2C=CH2; (C) H3C-CH3 drawn fully; (D) H3C-C≡C-CH3 drawn fully.

36.Write the structural formula of the unsaturated hydrocarbon having two carbon atoms with a double bond.

37.Write the IUPAC name of the given compound (CH2_22​=CH-CH3_33​).

39.Complete the given M-chart. HydrocarbonBondChemical NatureAdditional namesaturatedsingle covalentYparaffinsunsaturatedXunstable and more reactiveolefins Figure: M-chart table with blanks X (bond of unsaturated hydrocarbon) and Y (chemical nature of saturated hydrocarbon).

40.Write difference between alkane and alkyne on the basis of number of bonds and general molecular formula.

41.Write a difference between ethane and ethene.

42.Why are hydrocarbons called organic compounds?

43.Study the given bar diagram. Write the molecular structure and IUPAC name of the compound formed from the atoms of the elements of atomic mass given in the bar diagram. Figure: Bar graph with three bars: Mass of Carbon = 24, Mass of Hydrogen = 6, Mass of Oxygen = 16.

44.What is the name of the group of hydrocarbons with the general formula CnH2nC_nH_{2n}Cn​H2n​?

45.Write the name of an alkane having three carbon atoms.

46.What is a hydrocarbon?

47.Define functional group.

49.Write any two differences between homologous series and functional group.

50.Write any two differences between saturated and unsaturated hydrocarbons.

51.Write the structural formula of the following compounds. (a) C3H8O3C_3H_8O_3C3​H8​O3​, trihydric alcohol (glycerol) (b) C2H2C_2H_2C2​H2​, hydrocarbon OR Write any two differences between ethene and ethyne.

53.An organic compound has the elements C, H and O in it. It is used in thermometers. (a) Identify it and write its functional group. (b) Write its IUPAC name. (c) Write the name of the traditional method of preparation of this compound.

54.A hydrocarbon compound 'A' is used to preserve biological specimen and next hydrocarbon 'B' is used as sweetening agent in confectionery. (i) Write down the IUPAC name of compound 'A'. (ii) Write the structural formula of compound 'B'.

55.Write the structural formula of glycol.

56.Write the structural formula of ethanol.

57.A monohydric alcohol is used as thermometric liquid and as disinfectant in syringe and wounds. (a) Write the structural formula of that alcohol. (b) Write the molecular formula of the fourth member of the alcohol homologous series in which the given alcohol lies.

58.Write the molecular formula of the given compound (CH2_22​=CH-CH3_33​).

Write the structural formula of glycerol.

Write the IUPAC name and structural formula of the compound formed by replacing one hydrogen atom of each carbon atom of ethane by an -OH group.

Which one is the general molecular formula of alkene?
(a) $C_nH_{2n-2}$ (b) $C_nH_{2n}$ (c) $C_nH_{2n+1}$ (d) $C_nH_{2n+2}$

Write the IUPAC name of the given structural formula (CH3-CH2-OH).

Study the structure of the given organic compound (CH3-CH2-OH).
(a) Write the general molecular formula of the compound.
(b) In which group of organic compounds does this compound belong?

Which of the following is a tri-hydric alcohol?
(a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

Which of the following is a di-hydric alcohol?
(a) Ethanol (b) Ethylene glycol (c) Methanol (d) Glycerol

Which suffix is present in the name of hydrocarbons with general formula $C_nH_{2n-2}$ ?
(i) -ane (ii) -ene (iii) -ol (iv) -yne

Which suffix is present in the name of hydrocarbons with general formula $C_nH_{2n}$ ?
(a) -ane (b) -ene (c) -ol (d) -yne

A colourless viscous liquid hydrocarbon is used as a sweetening agent in confectionery.
(a) Write the IUPAC name of this compound.
(b) Write the structural formula of the compound formed by replacing all -OH by H.

Write the name of the member of alkyne which contains an equal number of hydrogen and carbon. Write its structural formula / one use of it.

Write an application of the given hydrocarbon in daily life.
Figure: Structural formula of propane-1,2,3-triol (glycerol): a chain of three carbon atoms, H-C-C-C-H, each carbon bearing one OH group on top and one H below.

Write the IUPAC name of the given compound (ethane). Write a use of the compound which is formed by replacing one hydrogen atom from each carbon by an -OH group.
Figure: Structural formula of ethane: two carbon atoms joined by a single bond, each carbon bonded to three hydrogen atoms (H3C-CH3).

A saturated hydrocarbon has its molecular mass 30 amu. Write the IUPAC name of the compound formed by replacing two -H atoms, one from each carbon atom, by one -OH group each. Also write one use of that compound.

Write the name and structural formula of the alcohol having two carbons.

Write a use of the organic compound given in the figure (ethanol).

Which compound is formed when one hydrogen of ethane is replaced by a hydroxide group?
(a) Ethane (b) Ethyne (c) Ethanol (d) Ethene

A student made a model of methane and another student made a model of propane. Their teacher removed one hydrogen atom from the terminal of each model and joined them together. Which hydrocarbon is formed? Write its structural formula too.

Write the structural formula of marsh gas. Write the IUPAC name of the compound formed when one 'H' of the hydrocarbon is replaced by one 'OH'.

Write the structural formula of the saturated hydrocarbon having molecular mass 44 amu. Write the IUPAC name of the compound which is obtained by removing two hydrogen atoms from adjacent carbons.

A saturated hydrocarbon has a molecular mass of 58 amu. Write its IUPAC name.

Which compound is formed by removing two hydrogen atoms from a saturated hydrocarbon with two carbons? Mention one application of the compound formed by adding one hydrogen atom to one carbon and one hydroxyl group to the other carbon.

Write the general molecular formula of the compound given ( $H-C\equiv C-H$ ). Also write the IUPAC name of the compound.
Figure: Structural formula of a compound: H-C≡C-H (ethyne/acetylene).

An organic compound is made up of two carbon atoms and two hydrogen atoms with general formula $C_nH_{2n-2}$ . Identify the compound.
(a) Ethane (b) Ethene (c) Ethyl (d) Ethyne

Write a general molecular formula of alkyne.

Which of the following is the alkyne having 5 carbon atoms?
(a) pentane (b) Pentene (c) Pentyne (d) Pentyl

Which of the following hydrocarbon groups belongs to alkyne?

`(A) H-C≡C-H (B) H2C=CH2 (C) H3C-CH3 (D) H3C-C≡C-CH3`
(a) A and C (b) A and B (c) A and D (d) B and C
Figure: Four structural formulas: (A) H-C≡C-H; (B) H2C=CH2; (C) H3C-CH3 drawn fully; (D) H3C-C≡C-CH3 drawn fully.

Write the structural formula of the unsaturated hydrocarbon having two carbon atoms with a double bond.

Write the IUPAC name of the given compound (CH $_2$ =CH-CH $_3$ ).

Complete the given M-chart.

Hydrocarbon Bond Chemical Nature Additional name
saturated single covalent Y paraffins
unsaturated X unstable and more reactive olefins
Figure: M-chart table with blanks X (bond of unsaturated hydrocarbon) and Y (chemical nature of saturated hydrocarbon).

Write difference between alkane and alkyne on the basis of number of bonds and general molecular formula.

Write a difference between ethane and ethene.

Why are hydrocarbons called organic compounds?

Study the given bar diagram. Write the molecular structure and IUPAC name of the compound formed from the atoms of the elements of atomic mass given in the bar diagram.
Figure: Bar graph with three bars: Mass of Carbon = 24, Mass of Hydrogen = 6, Mass of Oxygen = 16.

What is the name of the group of hydrocarbons with the general formula $C_nH_{2n}$ ?

Write the name of an alkane having three carbon atoms.

What is a hydrocarbon?

Define functional group.

Write any two differences between homologous series and functional group.

Write any two differences between saturated and unsaturated hydrocarbons.

Write the structural formula of the following compounds. (a) $C_3H_8O_3$ , trihydric alcohol (glycerol) (b) $C_2H_2$ , hydrocarbon
OR
Write any two differences between ethene and ethyne.

An organic compound has the elements C, H and O in it. It is used in thermometers. (a) Identify it and write its functional group. (b) Write its IUPAC name. (c) Write the name of the traditional method of preparation of this compound.

A hydrocarbon compound 'A' is used to preserve biological specimen and next hydrocarbon 'B' is used as sweetening agent in confectionery.
(i) Write down the IUPAC name of compound 'A'.
(ii) Write the structural formula of compound 'B'.

Write the structural formula of glycol.

Write the structural formula of ethanol.

A monohydric alcohol is used as thermometric liquid and as disinfectant in syringe and wounds.
(a) Write the structural formula of that alcohol.
(b) Write the molecular formula of the fourth member of the alcohol homologous series in which the given alcohol lies.

Write the molecular formula of the given compound (CH $_2$ =CH-CH $_3$ ).