Chapter 4

Chemistry

+2 college entrance (after SEE) past exam questions

Past questions and answers

78 questions set from this chapter, 15 of them more than once; 4 are most repeated (set, or a close variant set, in 3 or more exams). Most repeated first.

Most repeated · 4 of 18 exams
Asked 3 times
2083 · Science Model Set D · 1 mark
2083 · Science Model Set E · 1 mark
2080 · Science Model · 1 mark

The reaction between strong acid and weak base gives: (a) acidic salt (b) basic salt (c) neutral salt (d) normal salt

Similar questions: The reaction between strong acid and strong base (2083 · Science Model Set A)

Answer

(a) acidic salt

The salt of a strong acid and a weak base (for example $\mathrm{NH_4Cl}$ from HCl and $\mathrm{NH_4OH}$ ) hydrolyses in water to give an acidic solution with pH below 7.

Answer checked by Claude Sonnet · Oct 21, 2026

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Most repeated · 4 of 18 exams
2083 · Science Model Set A · 1 mark

The reaction between strong acid and strong base gives: (a) acidic salt (b) basic salt (c) both a and b (d) Neutral salt

Similar questions: The reaction between strong acid and weak base (2083 · Science Model Set D)

Answer

(d) Neutral salt

A strong acid and a strong base give a salt whose ions do not hydrolyse (for example NaCl), so the solution is neutral with pH 7.

Answer checked by Claude Sonnet · Oct 21, 2026

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Most repeated · 3 of 18 exams
Asked 2 times
2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

ZnO is an example of: (a) amphoteric oxide (b) acidic oxide (c) neutral oxide (d) basic oxide

Similar questions: The Nature of ZnO is (2083 · Science Model Set B)

Answer

(a) amphoteric oxide

ZnO reacts with both acids and bases:

$\mathrm{ZnO + 2HCl \to ZnCl_2 + H_2O}$

$\mathrm{ZnO + 2NaOH \to Na_2ZnO_2 + H_2O}$

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Most repeated · 3 of 18 exams
2083 · Science Model Set B · 1 mark

The Nature of ZnO is (a) acidic (b) basic (c) amphoteric (d) neutral 0 0

Similar questions: ZnO is an example of (2083 · Science Model Set D)

Answer

(c) amphoteric

ZnO reacts with both acids and bases, forming salts and water. For example $\mathrm{ZnO + 2HCl \to ZnCl_2 + H_2O}$ and $\mathrm{ZnO + 2NaOH \to Na_2ZnO_2 + H_2O}$ .

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2083 · Science Model Set A · 1 mark
2083 · Science Model Set C · 1 mark

Which color is imparted to the glass by using cuprous oxide? (a) Black (b) Purple (c) Red (d) Green

Answer

(c) Red

Cuprous oxide ( $\mathrm{Cu_2O}$ ) gives red-coloured glass (cupric oxide gives green or blue).

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2083 · Science Model Set A · 1 mark
2083 · Science Model Set B · 1 mark

The slaked lime is: (a) $\mathrm{MgCl_{2}}$ (b) CaO (c) $\mathrm{Ca(OH)_{2}}$ (d) $\mathrm{Mg(OH)_{2}}$

Answer

(c) $\mathrm{Ca(OH)_2}$

Slaked lime is formed when quicklime reacts with water: $\mathrm{CaO + H_2O \rightarrow Ca(OH)_2}$ .

Answer checked by Claude Sonnet · Oct 21, 2026

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

What is the colour of blue litmus paper in acidic solution? (a) red (b) blue (c) yellow (d) colourless

Answer

(a) red

Acids turn blue litmus red. Bases turn red litmus blue.

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

Which metal can be extracted from bauxite? (a) Fe (b) Zn (c) Al (d) Cu

Answer

(c) Al

Bauxite ( $\mathrm{Al_2O_3\cdot 2H_2O}$ ) is the chief ore of aluminium, extracted by electrolysis of alumina (Hall-Heroult process).

Answer checked by Claude Sonnet · Oct 21, 2026

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

Which of the following statement is correct? (a) Na is more reactive than K (b) Ca is less reactive than Mg (c) O has larger atomic size than S (d) none of the above

Answer

(d) none of the above

Na is less reactive than K (K lies below Na in group 1). Ca is more reactive than Mg (Ca lies below Mg in group 2). O is smaller than S, since atomic size increases down a group. So (a), (b) and (c) are all false.

Answer checked by Claude Sonnet · Oct 21, 2026

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

What is the pH value of products of neutralization reaction? (a) 5 (b) 6 (c) 7 (d) 8

Answer

(c) 7

Neutralization of a strong acid by a strong base gives a salt and water, which is neutral with pH 7.

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

What is the molecular weight of $\mathrm{Na_{2}SO_{4}}$ ? (a) 140 (b) 141 (c) 142 (d) 143

Answer

(c) 142

$M(\mathrm{Na_2SO_4}) = 2(23)+32+4(16)=46+32+64=142$

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

– COOH is the functional group of : (a) alcohol (b) ether (c) aldehyde (d) carboxylic acid

Answer

(d) carboxylic acid

The $-\mathrm{COOH}$ group is the carboxyl group, characteristic of carboxylic acids such as ethanoic acid.

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

The reaction between ammonia and carbon dioxide gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) none of these

Answer

(a) urea

Ammonia reacts with carbon dioxide under high temperature and pressure to form urea:

$2\mathrm{NH_3} + \mathrm{CO_2} \rightarrow \mathrm{NH_2CONH_2} + \mathrm{H_2O}$

Answer checked by Claude Sonnet · Oct 21, 2026

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

$\mathrm{CuSO_4\cdot 5H_2O}$ is the molecular formula of: (a) green vitriol (b) blue vitriol (c) white vitriol (d) none of these

Answer

(b) blue vitriol

Hydrated copper sulphate, $\mathrm{CuSO_4\cdot 5H_2O}$ , is blue vitriol. Green vitriol is $\mathrm{FeSO_4\cdot 7H_2O}$ and white vitriol is $\mathrm{ZnSO_4\cdot 7H_2O}$ .

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

Which colour get imparted in the glass by using chromium oxide? (a) Black (b) Blue (c) Green (d) Yellow

Answer

(c) Green

Chromium oxide ( $\mathrm{Cr_2O_3}$ ) gives green colour to glass.

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

The thick paste of cement and sand in the ratio of 1:3 with water is called (a) cement concrete (b) cement clinker (c) cement mortar (d) cement powder

Answer

(c) cement mortar

Cement mixed with sand (e.g. 1:3) and water forms a thick paste called cement mortar, used for plastering and joining bricks. Concrete also contains gravel.

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2083 · Science Model Set D · 1 mark
2080 · Science Model · 1 mark

The solution of calcium hydroxide is also called as (a) quick lime (b) slaked lime (c) lime water (d) both 'b' and 'c'

Answer

(c) lime water

Calcium hydroxide, $\mathrm{Ca(OH)_2}$ , is called slaked lime when solid; its clear aqueous solution is called lime water (it turns milky with $\mathrm{CO_2}$ ).

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2083 · Science Model Set A · 1 mark

The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A

Similar questions: The position of alkaline earth metal is (2083 · Science Model Set B)

Answer

(b) II A

The alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra) form group IIA.

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2083 · Science Model Set B · 1 mark

The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A 6 2

Similar questions: The position of alkaline earth metal is (2083 · Science Model Set A)

Answer

(b) II A

Alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra) have two valence electrons ( $ns^2$ ), so they lie in group II A (group 2).

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2083 · Science Model Set E · 1 mark

The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) carbonization

Similar questions: The nature of soap is (2079 · Science Model)

Answer

(a) bio-degradable

Soap is made from natural fats and oils, so micro-organisms can break it down. It forms scum in hard water, and non-biodegradability is a property of detergents.

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2079 · Science Model · 1 mark

The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) none of the above

Similar questions: The nature of soap is (2083 · Science Model Set E)

Answer

(a) bio-degradable

Soap is the sodium or potassium salt of long-chain fatty acids and is broken down by microorganisms. In hard water it forms insoluble scum with $\mathrm{Ca^{2+}}$ and $\mathrm{Mg^{2+}}$ , so it is not easily soluble there.

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2083 · Science Model Set A · 1 mark

The number of atoms of oxygen present in the ozone are. (a) 3 (b) 4 (c) 2 (d) 1

Answer

(a) 3

Ozone is a molecule of formula $\mathrm{O_3}$ , so it has three oxygen atoms.

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2083 · Science Model Set A · 1 mark

In modern periodic table, the elements placed in VIIA are (a) Halogen (b) alkaline earth metal (c) alkali metal (d) inert gas

Answer

(a) Halogen

Group VIIA contains F, Cl, Br, I and At, which are the halogens.

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2083 · Science Model Set A · 1 mark

In the decomposition of limestone, $\mathrm{CaCO_3 \xrightarrow{\Delta} A + CO_2}$ , A is also called as: (a) Lime water (b) Slaked lime (c) quick lime (d) milk of lime

Answer

(c) quick lime

$\mathrm{CaCO_3 \xrightarrow{\Delta} CaO + CO_2}$

A is CaO, which is called quick lime.

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2083 · Science Model Set A · 1 mark

Bauxite is used to extract: (a) Cu (b) Al (c) Fe (d) Zn

Answer

(b) Al

Bauxite ( $\mathrm{Al_2O_3\cdot 2H_2O}$ ) is the principal ore of aluminium, extracted by the Hall–Héroult electrolytic process.

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2083 · Science Model Set A · 1 mark

Which alkali metal gives golden yellow color to the flame? (a) Na (b) K (c) Rb (d) Fr

Answer

(a) Na

Sodium salts impart a golden yellow colour to the flame (K gives lilac, Rb red-violet).

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2083 · Science Model Set A · 1 mark

In the Haber’s synthesis of ammonia, the ratio of $\mathrm{N_{2}}$ and $\mathrm{H_{2}}$ is (a) 1:1 (b) 1:2 (c) 1:3 (d) 1:4

Answer

(c) 1:3

$\mathrm{N_2 + 3H_2 \rightleftharpoons 2NH_3}$

Nitrogen and hydrogen are taken in the volume ratio 1:3.

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2083 · Science Model Set A · 1 mark

In which of the following glasses, boric oxide is used? (a) Silica (b) borosilicate (c) water (d) ordinary

Answer

(b) borosilicate

Borosilicate (Pyrex) glass is made using boric oxide $\mathrm{B_2O_3}$ ; it resists heat and thermal shock.

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2083 · Science Model Set A · 1 mark

−COOH is the functional group of (a) Carboxylic acid (b) Ester (c) alcohol (d) Ketone

Answer

(a) Carboxylic acid

The $-\mathrm{COOH}$ group is the carboxyl group, characteristic of carboxylic acids.

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2083 · Science Model Set A · 1 mark

Which of the following is basic oxide? (a) $\mathrm{CO_{2}}$ (b) $\mathrm{Na_{2}O}$ (c) MgO (d) both b and c

Answer

(d) both b and c

$\mathrm{Na_2O}$ and MgO are oxides of metals and are basic; $\mathrm{CO_2}$ is an acidic oxide.

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2083 · Science Model Set A · 1 mark

Which of the following is bio-degradable? (a) plastic (b) detergents (c) pesticides (d) soap

Answer

(d) soap

Soaps have straight hydrocarbon chains that microbes can break down. Plastics, pesticides and branched-chain detergents resist biodegradation.

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2083 · Science Model Set B · 1 mark

Which of the following statements is not true for plastic waste? (a) Can be used to make compost (b) It lasts for a longer period of time (c) Toxic fumes are produced when burnt (d) All of the above

Answer

(a) Can be used to make compost

Plastic is non-biodegradable, so it persists for a very long time and releases toxic fumes when burnt. It cannot be composted, so statement (a) is the one that is not true.

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2083 · Science Model Set B · 1 mark

The electronic configuration of an element is $[\mathrm{Ar}]\,3d^{6}4s^{2}$ . The element is: (a) Fe (b) Cu (c) Mn (d) Cr

Answer

(a) Fe

The configuration $[\mathrm{Ar}]\,3d^{6}4s^{2}$ has $18 + 6 + 2 = 26$ electrons, so $Z = 26$ , which is iron. Mn has $3d^5 4s^2$ , Cu has $3d^{10}4s^1$ and Cr has $3d^5 4s^1$ .

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2083 · Science Model Set B · 1 mark

The reaction, $\mathrm{AgNO_{3}}$ + NaCl → AgCl + $\mathrm{NaNO_{3}}$ is (a) Neutralization (b) decomposition (c) single displacement (d) double displacement

Answer

(d) double displacement

The two compounds exchange ions: $\mathrm{Ag^+}$ pairs with $\mathrm{Cl^-}$ and $\mathrm{Na^+}$ with $\mathrm{NO_3^-}$ . AgCl is precipitated, which is a double displacement (precipitation) reaction.

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2083 · Science Model Set B · 1 mark

Galena is the ore of (a) Pb (b) cu (c) Hg (d) Fe

Answer

(a) Pb

Galena is lead sulphide, PbS, the main ore of lead.

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2083 · Science Model Set B · 1 mark

Brass is an alloy of (a) Cu and Zn (b) Cu and Fe (c) Zn and Fe (d) Cu and Mg

Answer

(a) Cu and Zn

Brass is an alloy of copper (about 60-70%) and zinc (about 30-40%).

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2083 · Science Model Set B · 1 mark

The producer gas is (a) $\mathrm{CO + H_2}$ (b) $\mathrm{CO + N_2}$ (c) $\mathrm{CO + O_2}$ (d) $\mathrm{CO + H_2O}$

Answer

(b) $\mathrm{CO + N_2}$

Producer gas is made by passing air over red-hot coke. It is a mixture of carbon monoxide (about 25-30%) and nitrogen (about 65-70%). The nitrogen comes from the air. Water gas is the mixture of $\mathrm{CO + H_2}$ .

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2083 · Science Model Set B · 1 mark

To impart red color in the glass, the metallic oxide used is (a) Cupric oxide (b) Cuprous Oxide (c) Chromium Oxide (d) Both a and b

Answer

(b) Cuprous oxide

Cuprous oxide, $\mathrm{Cu_2O}$ , gives red colour to glass. Cupric oxide, CuO, gives blue or green, and chromium oxide gives green.

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2083 · Science Model Set B · 1 mark

In the mortar, the ratio of cement and sand is (a) 1: 1 (b) 1: 2 (c) 1: 3 (d) 1: 4

Answer

(c) 1 : 3

Mortar is a mixture of cement, sand and water. In the standard textbook form the cement : sand ratio is 1 : 3, though it varies with the use.

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2083 · Science Model Set B · 1 mark

Which of the following element is tetravalent? (a) Na (b) C (c) Al (d) K

Answer

(b) C

Carbon has configuration $2,4$ , so it has four valence electrons and valency 4. Na and K have valency 1 and Al has valency 3.

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2083 · Science Model Set B · 1 mark

The milk of magnesia is (a) $\mathrm{Mg(OH)_{2}}$ (b) $\mathrm{MgSO_{4}}$ (c) $\mathrm{MgCl_{2}}$ (d) MgO

Answer

(a) $\mathrm{Mg(OH)_{2}}$

Milk of magnesia is a suspension of magnesium hydroxide in water. It is used as an antacid.

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2083 · Science Model Set B · 1 mark

Glycerol is also called as: (a) phenol (b) methanol (c) glycerine (d) glycol

Answer

(c) glycerine

Glycerol (propane-1,2,3-triol) is commonly called glycerine.

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2083 · Science Model Set C · 1 mark

The water soluble basic gas is (a) $\mathrm{CO_{2}}$ (b) $\mathrm{H_{2}}$ (c) $\mathrm{NH_{3}}$ (d) $\mathrm{N_{2}}$

Answer

(c) $\mathrm{NH_3}$

Ammonia is highly soluble in water and forms $\mathrm{NH_4OH}$ , a weak base: $\mathrm{NH_3 + H_2O \rightleftharpoons NH_4^+ + OH^-}$ .

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2083 · Science Model Set C · 1 mark

Lead crystal glass is made by adding (a) lead monoxide (b) lead peroxide (c) lead super oxide (d) both a and b

Answer

(a) lead monoxide

Lead crystal glass is made by adding lead monoxide (PbO) in place of lime (CaO) in the glass mixture, giving a dense glass with high refractive index and brilliance.

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2083 · Science Model Set C · 1 mark

The functional group of Carboxylic acid is ? (a) −OH (b) −CHO (c) −COOH (d) −CN

Answer

(c) $-\mathrm{COOH}$

The carboxyl group (carbonyl plus hydroxyl on the same carbon) characterises carboxylic acids.

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2083 · Science Model Set C · 1 mark

$\mathrm{Na_{2}CO_{3}}$ is an example of (a) Acidic salt (b) basic salt (c) Neutral salt (d) Normal salt

Answer

(d) Normal salt

$\mathrm{Na_2CO_3}$ is formed by complete replacement of the hydrogen of $\mathrm{H_2CO_3}$ by sodium, so it is a normal salt (though its solution is alkaline).

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2083 · Science Model Set C · 1 mark

MgO and $\mathrm{Na_{2}}$ O are example of (a) acidic oxide (b) Neutral Oxide (c) Basic Oxide (d) Peroxide

Answer

(c) Basic Oxide

Oxides of metals such as MgO and $\mathrm{Na_2O}$ react with acids to form salt and water, and with water to give bases.

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2083 · Science Model Set C · 1 mark

Ant bite contain (a) citric acid (b) formic acid (c) acetic acid (d) lactic acid

Answer

(b) formic acid

Ant stings inject formic acid (methanoic acid, HCOOH), which causes the burning pain.

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2083 · Science Model Set C · 1 mark

Baking powder is prepared from (a) $\mathrm{Na_{2}Co_{3}}$ (b) NaOH (c) $\mathrm{NaHCO_{3}}$ (d) NAcl

Answer

(c) $\mathrm{NaHCO_3}$

Baking powder is sodium hydrogencarbonate mixed with a mild edible acid such as tartaric acid.

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2083 · Science Model Set C · 1 mark

In the reaction, $\mathrm{2NH_4Cl + P \xrightarrow{\Delta} CaCl_2 + 2H_2O + 2NH_3\uparrow}$ , the 'P' is (a) $\mathrm{Mg(OH)_2}$ (b) NaOH (c) $\mathrm{Al(OH)_3}$ (d) $\mathrm{Ca(OH)_2}$

Answer

(d) $\mathrm{Ca(OH)_2}$

Heating ammonium chloride with slaked lime gives ammonia:

$\mathrm{2NH_4Cl + Ca(OH)_2 \xrightarrow{\Delta} CaCl_2 + 2H_2O + 2NH_3\uparrow}$

The equation balances with Ca on the right, which fixes P as calcium hydroxide.

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2083 · Science Model Set C · 1 mark

Hematite is the ore of (a) Fe (b) Cu (c) pb (d) Al

Answer

(a) Fe

Hematite is $\mathrm{Fe_2O_3}$ , an ore of iron.

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2083 · Science Model Set C · 1 mark

Which of the following is not alkali metal? (a) Na (b) Ca (c) K (d) Fr

Answer

(b) Ca

Na, K and Fr belong to Group 1 (alkali metals). Ca is in Group 2 and is an alkaline earth metal.

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2083 · Science Model Set C · 1 mark

The chief ore to extract the copper is (a) Copper pyrite (b) Cuprite (c) azurite (d) malachite

Answer

(a) Copper pyrite

Copper pyrite ( $\mathrm{CuFeS_2}$ ) is the chief ore of copper, supplying most of the metal extracted worldwide. Cuprite, azurite and malachite are minor ores.

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2083 · Science Model Set C · 1 mark

How many isotopes does Hydrogen have? (a) 1 (b) 2 (c) 3 (d) 4

Answer

(c) 3

Hydrogen has three isotopes: protium ( $^1_1\mathrm{H}$ ), deuterium ( $^2_1\mathrm{H}$ ) and tritium ( $^3_1\mathrm{H}$ ).

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2083 · Science Model Set E · 1 mark

Which is the most abundant metal in the earth crust? (a) Al (b) Fe (c) Cu (d) Pb

Answer

(a) Al

Aluminium is the most abundant metal in the earth's crust (about 8%); oxygen and silicon are the most abundant elements overall.

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2083 · Science Model Set E · 1 mark

Isotopes have the same (a) atomic number (b) mass no. and atomic no. (c) neutron number (d) mass number

Answer

(a) atomic number

Isotopes are atoms of the same element, so they have the same number of protons (atomic number) but different numbers of neutrons and hence different mass numbers.

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2083 · Science Model Set E · 1 mark

Mercury is extracted from (a) cinnabar (b) haematite (c) bauxite (d) cuprite

Answer

(a) cinnabar

The ore of mercury is cinnabar (HgS). Haematite is an ore of iron, bauxite of aluminium and cuprite of copper.

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2083 · Science Model Set E · 1 mark

The molecular formula of slaked lime is, (a) CaO (b) $\mathrm{Ca(OH)_{2}}$ (c) $\mathrm{Mg(OH)_{2}}$ (d) MgO

Answer

(b) $\mathrm{Ca(OH)_{2}}$

Slaked lime is calcium hydroxide, formed when quicklime (CaO) reacts with water: $\mathrm{CaO + H_2O \to Ca(OH)_2}$ .

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2083 · Science Model Set E · 1 mark

Which of the following is an amphoteric oxide? (a) $\mathrm{CO_{2}}$ (b) NO (c) $\mathrm{NO_{2}}$ (d) ZnO

Answer

(d) ZnO

An amphoteric oxide reacts with both acids and bases. ZnO does so, giving zinc salts with acids and zincates with alkalis. $\mathrm{CO_2}$ and $\mathrm{NO_2}$ are acidic, and NO is neutral.

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2083 · Science Model Set E · 1 mark

The reaction between ammonia and $\mathrm{CO_{2}}$ gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) ammonium sulphate

Answer

(a) urea

Ammonia and carbon dioxide react under high pressure and temperature to form urea: $\mathrm{2NH_3 + CO_2 \to NH_2CONH_2 + H_2O}$

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2083 · Science Model Set E · 1 mark

Which acid is found in Coca-Cola? (a) Sulphuric acid (b) Nitric acid (c) Formic acid (d) Carbonic acid

Answer

(d) Carbonic acid

Coca-Cola is a carbonated drink. Dissolved $\mathrm{CO_2}$ forms carbonic acid, $\mathrm{H_2CO_3}$ .

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2083 · Science Model Set E · 1 mark

Dry ice is formed by cooling (a) $\mathrm{CO_{2}}$ gas (b) $\mathrm{O_{2}}$ gas (c) $\mathrm{N_{2}}$ gas (d) $\mathrm{SO_{2}}$ gas

Answer

(a) $\mathrm{CO_{2}}$ gas

Dry ice is solid carbon dioxide, obtained by compressing and cooling $\mathrm{CO_2}$ gas. It sublimes directly to gas without melting.

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2083 · Science Model Set E · 1 mark

The molecular formula of Gypsum is (a) $\mathrm{CaSO_4\cdot\frac{1}{2}H_2O}$ (b) $\mathrm{CaSO_4\cdot H_2O}$ (c) $\mathrm{CaSO_4\cdot 2H_2O}$ (d) $\mathrm{CaSO_4\cdot 3H_2O}$

Answer

(c) $\mathrm{CaSO_4\cdot 2H_2O}$

Gypsum is hydrated calcium sulphate with two molecules of water of crystallisation. On heating to about $120^\circ$ C it gives plaster of Paris, $\mathrm{CaSO_4\cdot\frac12H_2O}$ .

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2083 · Science Model Set E · 1 mark

Which of the following is an organophosphrus insecticide? (a) DDT (b) BHC (c) Baygon (d) Malathion

Answer

(d) Malathion

Malathion is an organophosphorus insecticide. DDT and BHC are organochlorines, and Baygon is a carbamate.

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2083 · Science Model Set E · 1 mark

$\mathrm{MgSO_4\cdot 7H_2O}$ is the molecular formula of (a) common salt (b) gypsum salt (c) terrous salt (d) epsom salt

Answer

(d) epsom salt

$\mathrm{MgSO_4\cdot 7H_2O}$ is magnesium sulphate heptahydrate, known as Epsom salt.

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2083 · Science Model Set E · 1 mark

The molecular weight of $\mathrm{K_{2}SO_{4}}$ is (a) 171 (b) 172 (c) 173 (d) 174

Answer

(d) 174

$M(\mathrm{K_2SO_4}) = 2(39)+32+4(16)=78+32+64=174$

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2083 · Science Model Set E · 1 mark

CnH2n+2 is the molecular formula of , (a) saturated hydrocarbon (b) alkene (c) alkyne (d) alcohol

Answer

(a) saturated hydrocarbon

$\mathrm{C_nH_{2n+2}}$ is the general formula of alkanes, which are saturated hydrocarbons. Alkenes are $\mathrm{C_nH_{2n}}$ and alkynes are $\mathrm{C_nH_{2n-2}}$ .

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2079 · Science Model · 1 mark

Silver metal can be extracted from (a) haematite (b) argentite (c) chalcopyrite (d) bauxite

Answer

(b) argentite

Argentite ( $\mathrm{Ag_2S}$ ) is the chief ore of silver. Haematite is an ore of iron, chalcopyrite of copper and bauxite of aluminium.

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2079 · Science Model · 1 mark

Which of the following is trihydric alcohol? (a) methanol (b) ethanol (c) propanol (d) glycerol

Answer

(d) glycerol

Glycerol (propane-1,2,3-triol, $\mathrm{C_3H_5(OH)_3}$ ) has three $-\mathrm{OH}$ groups, so it is a trihydric alcohol. Methanol, ethanol and propanol are monohydric.

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2079 · Science Model · 1 mark

CnH2n-2 is the general formula of (a) alkane (b) alkene (c) alkyne (d) alcohol

Answer

(c) alkyne

Alkynes contain a carbon-carbon triple bond and have general formula $\mathrm{C_nH_{2n-2}}$ (for example ethyne, $\mathrm{C_2H_2}$ ). Alkanes are $\mathrm{C_nH_{2n+2}}$ and alkenes $\mathrm{C_nH_{2n}}$ .

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2079 · Science Model · 1 mark

$\mathrm{Fe_{3}O_{4}}$ is an example of (a) acidic oxide (b) basic oxide (c) neutral oxide (d) mixed oxide

Answer

(d) mixed oxide

$\mathrm{Fe_3O_4}$ is a combination of $\mathrm{FeO}$ and $\mathrm{Fe_2O_3}$ ( $\mathrm{FeO\cdot Fe_2O_3}$ ), so it is a mixed oxide.

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2079 · Science Model · 1 mark

Which colour is imparted to the glass by using manganese oxide? (a) Purple (b) Black (c) Blue (d) Green

Answer

(a) Purple

Manganese oxide ( $\mathrm{MnO_2}$ ) gives glass a purple (amethyst) colour. It is also used to remove the green tint caused by iron impurities.

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2079 · Science Model · 1 mark

$\mathrm{NaAlO_{2}}$ is the molecular formula of : (a) Sodium alumina oxide (b) Sodium meta-aluminate (c) Sodium alumina (d) none of the above

Answer

(b) Sodium meta-aluminate

$\mathrm{NaAlO_2}$ is the salt formed when aluminium hydroxide or alumina reacts with sodium hydroxide, and it is named sodium meta-aluminate.

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2079 · Science Model · 1 mark

Which of the following statement is correct? (a) Na is more reactive than li due to more electron (b) Both a and b (c) F is more reactive because it is metal (d) None of the above

Answer

(a) Na is more reactive than Li due to more electron

Reactivity of alkali metals increases down the group. Na has its outer electron in a higher shell, farther from the nucleus and more shielded, so it is lost more easily than in Li. The other options are wrong: fluorine is a non-metal, and option (b) is meaningless.

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2079 · Science Model · 1 mark

"KCl and $\mathrm{O_{2}}$ are formed by heating $\mathrm{KClO_{3}}$ ", what type of chemical reaction is this (a) Neutralization (b) Single displacement (c) Decomposition (d) Combination

Answer

(c) Decomposition

One compound splits into simpler substances on heating: $2\mathrm{KClO_3}\xrightarrow{\Delta}2\mathrm{KCl}+3\mathrm{O_2}$

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2079 · Science Model · 1 mark

Pick out weak acid from the following (a) $\mathrm{HNO_{3}}$ (b) $\mathrm{CH_{3}COOH}$ (c) $\mathrm{H_{2}SO_{4}}$ (d) HCl

Answer

(b) $\mathrm{CH_3COOH}$

Acetic acid ionises only partially in water. $\mathrm{HNO_3}$ , $\mathrm{H_2SO_4}$ and $\mathrm{HCl}$ are strong acids that ionise almost completely.

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2079 · Science Model · 1 mark

The reaction from NaOH and $\mathrm{CH_{3}COOH}$ gives (a) Basic Salt (b) Acidic Salt (c) Normal Salt (d) Neutral Salt

Answer

(c) Normal Salt

$\mathrm{NaOH}+\mathrm{CH_3COOH}\rightarrow \mathrm{CH_3COONa}+\mathrm{H_2O}$ All replaceable $\mathrm{H^+}$ of the acid and all $\mathrm{OH^-}$ of the base are neutralised, so sodium acetate is a normal salt.

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2079 · Science Model · 1 mark

The molecular formula of sodium thiosulphate is, (a) $\mathrm{Na_{2}S_{2}O_{2}}$ (b) $\mathrm{Na_{2}S_{4}O_{6}}$ (c) $\mathrm{Na_{2}SO_{4}}$ (d) $\mathrm{Na_{2}S_{2}O_{3}}$

Answer

(d) $\mathrm{Na_2S_2O_3}$

Sodium thiosulphate is $\mathrm{Na_2S_2O_3}$ (hypo). $\mathrm{Na_2S_4O_6}$ is sodium tetrathionate and $\mathrm{Na_2SO_4}$ is sodium sulphate.

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Questions from Kathmandu Model Secondary School (KMC) Entrance Model Questions, Science Set A (College-published model question set for the Class 11 Science entrance (100 MCQs: English, Science, Mathematics), 2083 BS; practice paper, not a recalled board paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Management and Law Set A (College-published model question set for the Class 11 Management and Law entrance (English, Mathematics, GK), 2083 BS; practice paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Science Set B (College-published model question set for the Class 11 Science entrance (100 MCQs: English, Science, Mathematics), 2083 BS; practice paper, not a recalled board paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Management and Law Set B (College-published model question set for the Class 11 Management and Law entrance (English, Mathematics, GK), 2083 BS; practice paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Science Set C (College-published model question set for the Class 11 Science entrance (100 MCQs: English, Science, Mathematics), 2083 BS; practice paper, not a recalled board paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Management and Law Set C (College-published model question set for the Class 11 Management and Law entrance (English, Mathematics, GK), 2083 BS; practice paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Science Set D (College-published model question set for the Class 11 Science entrance (100 MCQs: English, Science, Mathematics), 2083 BS; practice paper, not a recalled board paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Management and Law Set D (College-published model question set for the Class 11 Management and Law entrance (English, Mathematics, GK), 2083 BS; practice paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Science Set E (College-published model question set for the Class 11 Science entrance (100 MCQs: English, Science, Mathematics), 2083 BS; practice paper, not a recalled board paper), Kathmandu Model Secondary School (KMC) Entrance Model Questions, Management and Law Set E (College-published model question set for the Class 11 Management and Law entrance (English, Mathematics, GK), 2083 BS; practice paper), Kathmandu Model Secondary School (KMC) Model Question 2080, Science (College model paper (Set B) for the Class 11 Science entrance (100 MCQs: Science 40, English 20, Mathematics 40), 2080 BS; also posted as page images on bishalkafle.com.np (2023)), Kathmandu Model Secondary School (KMC) Model Questions 2022 (2079 BS), Science (College model paper for the Class 11 Science entrance (100 MCQs: English 20, Science 40, Mathematics 40), July 2022), Kathmandu Model Secondary School (KMC) Model Questions 2022 (2079 BS), Management (College model paper for the Class 11 Management entrance (English, Mathematics, GK), July 2022), Kathmandu Model Secondary School (KMC) Model Question 2080 Management and Law, Set I (College model paper for the Class 11 Management and Law entrance (English, Mathematics, GK), 2080 BS; same questions as Set B of the later 2083 release) and KMC Entrance Model Questions, Science (first release, May 2026) (Earlier posting of the 2083 science sets; a few physics questions were later replaced). Answers are written for this site; check them against your class notes.

Past questions and answers

1.The reaction between strong acid and weak base gives: (a) acidic salt (b) basic salt (c) neutral salt (d) normal salt

2.The reaction between strong acid and strong base gives: (a) acidic salt (b) basic salt (c) both a and b (d) Neutral salt

3.ZnO is an example of: (a) amphoteric oxide (b) acidic oxide (c) neutral oxide (d) basic oxide

4.The Nature of ZnO is (a) acidic (b) basic (c) amphoteric (d) neutral 0 0

5.Which color is imparted to the glass by using cuprous oxide? (a) Black (b) Purple (c) Red (d) Green

6.The slaked lime is: (a) MgCl2\mathrm{MgCl_{2}}MgCl2​ (b) CaO (c) Ca(OH)2\mathrm{Ca(OH)_{2}}Ca(OH)2​ (d) Mg(OH)2\mathrm{Mg(OH)_{2}}Mg(OH)2​

7.What is the colour of blue litmus paper in acidic solution? (a) red (b) blue (c) yellow (d) colourless

8.Which metal can be extracted from bauxite? (a) Fe (b) Zn (c) Al (d) Cu

9.Which of the following statement is correct? (a) Na is more reactive than K (b) Ca is less reactive than Mg (c) O has larger atomic size than S (d) none of the above

10.What is the pH value of products of neutralization reaction? (a) 5 (b) 6 (c) 7 (d) 8

11.What is the molecular weight of Na2SO4\mathrm{Na_{2}SO_{4}}Na2​SO4​? (a) 140 (b) 141 (c) 142 (d) 143

12.– COOH is the functional group of : (a) alcohol (b) ether (c) aldehyde (d) carboxylic acid

13.The reaction between ammonia and carbon dioxide gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) none of these

14.CuSO4⋅5H2O\mathrm{CuSO_4\cdot 5H_2O}CuSO4​⋅5H2​O is the molecular formula of: (a) green vitriol (b) blue vitriol (c) white vitriol (d) none of these

15.Which colour get imparted in the glass by using chromium oxide? (a) Black (b) Blue (c) Green (d) Yellow

16.The thick paste of cement and sand in the ratio of 1:3 with water is called (a) cement concrete (b) cement clinker (c) cement mortar (d) cement powder

17.The solution of calcium hydroxide is also called as (a) quick lime (b) slaked lime (c) lime water (d) both 'b' and 'c'

18.The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A

19.The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A 6 2

20.The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) carbonization

21.The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) none of the above

22.The number of atoms of oxygen present in the ozone are. (a) 3 (b) 4 (c) 2 (d) 1

23.In modern periodic table, the elements placed in VIIA are (a) Halogen (b) alkaline earth metal (c) alkali metal (d) inert gas

24.In the decomposition of limestone, CaCO3→ΔA+CO2\mathrm{CaCO_3 \xrightarrow{\Delta} A + CO_2}CaCO3​Δ​A+CO2​, A is also called as: (a) Lime water (b) Slaked lime (c) quick lime (d) milk of lime

25.Bauxite is used to extract: (a) Cu (b) Al (c) Fe (d) Zn

26.Which alkali metal gives golden yellow color to the flame? (a) Na (b) K (c) Rb (d) Fr

27.In the Haber’s synthesis of ammonia, the ratio of N2\mathrm{N_{2}}N2​ and H2\mathrm{H_{2}}H2​ is (a) 1:1 (b) 1:2 (c) 1:3 (d) 1:4

28.In which of the following glasses, boric oxide is used? (a) Silica (b) borosilicate (c) water (d) ordinary

29.−COOH is the functional group of (a) Carboxylic acid (b) Ester (c) alcohol (d) Ketone

30.Which of the following is basic oxide? (a) CO2\mathrm{CO_{2}}CO2​ (b) Na2O\mathrm{Na_{2}O}Na2​O (c) MgO (d) both b and c

31.Which of the following is bio-degradable? (a) plastic (b) detergents (c) pesticides (d) soap

32.Which of the following statements is not true for plastic waste? (a) Can be used to make compost (b) It lasts for a longer period of time (c) Toxic fumes are produced when burnt (d) All of the above

33.The electronic configuration of an element is [Ar] 3d64s2[\mathrm{Ar}]\,3d^{6}4s^{2}[Ar]3d64s2. The element is: (a) Fe (b) Cu (c) Mn (d) Cr

34.The reaction, AgNO3\mathrm{AgNO_{3}}AgNO3​ + NaCl → AgCl + NaNO3\mathrm{NaNO_{3}}NaNO3​ is (a) Neutralization (b) decomposition (c) single displacement (d) double displacement

35.Galena is the ore of (a) Pb (b) cu (c) Hg (d) Fe

36.Brass is an alloy of (a) Cu and Zn (b) Cu and Fe (c) Zn and Fe (d) Cu and Mg

37.The producer gas is (a) CO+H2\mathrm{CO + H_2}CO+H2​ (b) CO+N2\mathrm{CO + N_2}CO+N2​ (c) CO+O2\mathrm{CO + O_2}CO+O2​ (d) CO+H2O\mathrm{CO + H_2O}CO+H2​O

38.To impart red color in the glass, the metallic oxide used is (a) Cupric oxide (b) Cuprous Oxide (c) Chromium Oxide (d) Both a and b

39.In the mortar, the ratio of cement and sand is (a) 1: 1 (b) 1: 2 (c) 1: 3 (d) 1: 4

40.Which of the following element is tetravalent? (a) Na (b) C (c) Al (d) K

41.The milk of magnesia is (a) Mg(OH)2\mathrm{Mg(OH)_{2}}Mg(OH)2​ (b) MgSO4\mathrm{MgSO_{4}}MgSO4​ (c) MgCl2\mathrm{MgCl_{2}}MgCl2​ (d) MgO

42.Glycerol is also called as: (a) phenol (b) methanol (c) glycerine (d) glycol

43.The water soluble basic gas is (a) CO2\mathrm{CO_{2}}CO2​ (b) H2\mathrm{H_{2}}H2​ (c) NH3\mathrm{NH_{3}}NH3​ (d) N2\mathrm{N_{2}}N2​

44.Lead crystal glass is made by adding (a) lead monoxide (b) lead peroxide (c) lead super oxide (d) both a and b

45.The functional group of Carboxylic acid is ? (a) −OH (b) −CHO (c) −COOH (d) −CN

46.Na2CO3\mathrm{Na_{2}CO_{3}}Na2​CO3​ is an example of (a) Acidic salt (b) basic salt (c) Neutral salt (d) Normal salt

47.MgO and Na2\mathrm{Na_{2}}Na2​ O are example of (a) acidic oxide (b) Neutral Oxide (c) Basic Oxide (d) Peroxide

48.Ant bite contain (a) citric acid (b) formic acid (c) acetic acid (d) lactic acid

49.Baking powder is prepared from (a) Na2Co3\mathrm{Na_{2}Co_{3}}Na2​Co3​ (b) NaOH (c) NaHCO3\mathrm{NaHCO_{3}}NaHCO3​ (d) NAcl

51.Hematite is the ore of (a) Fe (b) Cu (c) pb (d) Al

52.Which of the following is not alkali metal? (a) Na (b) Ca (c) K (d) Fr

53.The chief ore to extract the copper is (a) Copper pyrite (b) Cuprite (c) azurite (d) malachite

54.How many isotopes does Hydrogen have? (a) 1 (b) 2 (c) 3 (d) 4

55.Which is the most abundant metal in the earth crust? (a) Al (b) Fe (c) Cu (d) Pb

56.Isotopes have the same (a) atomic number (b) mass no. and atomic no. (c) neutron number (d) mass number

57.Mercury is extracted from (a) cinnabar (b) haematite (c) bauxite (d) cuprite

58.The molecular formula of slaked lime is, (a) CaO (b) Ca(OH)2\mathrm{Ca(OH)_{2}}Ca(OH)2​ (c) Mg(OH)2\mathrm{Mg(OH)_{2}}Mg(OH)2​ (d) MgO

59.Which of the following is an amphoteric oxide? (a) CO2\mathrm{CO_{2}}CO2​ (b) NO (c) NO2\mathrm{NO_{2}}NO2​ (d) ZnO

60.The reaction between ammonia and CO2\mathrm{CO_{2}}CO2​ gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) ammonium sulphate

61.Which acid is found in Coca-Cola? (a) Sulphuric acid (b) Nitric acid (c) Formic acid (d) Carbonic acid

62.Dry ice is formed by cooling (a) CO2\mathrm{CO_{2}}CO2​ gas (b) O2\mathrm{O_{2}}O2​ gas (c) N2\mathrm{N_{2}}N2​ gas (d) SO2\mathrm{SO_{2}}SO2​ gas

63.The molecular formula of Gypsum is (a) CaSO4⋅12H2O\mathrm{CaSO_4\cdot\frac{1}{2}H_2O}CaSO4​⋅21​H2​O (b) CaSO4⋅H2O\mathrm{CaSO_4\cdot H_2O}CaSO4​⋅H2​O (c) CaSO4⋅2H2O\mathrm{CaSO_4\cdot 2H_2O}CaSO4​⋅2H2​O (d) CaSO4⋅3H2O\mathrm{CaSO_4\cdot 3H_2O}CaSO4​⋅3H2​O

64.Which of the following is an organophosphrus insecticide? (a) DDT (b) BHC (c) Baygon (d) Malathion

65.MgSO4⋅7H2O\mathrm{MgSO_4\cdot 7H_2O}MgSO4​⋅7H2​O is the molecular formula of (a) common salt (b) gypsum salt (c) terrous salt (d) epsom salt

66.The molecular weight of K2SO4\mathrm{K_{2}SO_{4}}K2​SO4​ is (a) 171 (b) 172 (c) 173 (d) 174

67.CnH2n+2 is the molecular formula of , (a) saturated hydrocarbon (b) alkene (c) alkyne (d) alcohol

68.Silver metal can be extracted from (a) haematite (b) argentite (c) chalcopyrite (d) bauxite

69.Which of the following is trihydric alcohol? (a) methanol (b) ethanol (c) propanol (d) glycerol

70.CnH2n-2 is the general formula of (a) alkane (b) alkene (c) alkyne (d) alcohol

71.Fe3O4\mathrm{Fe_{3}O_{4}}Fe3​O4​ is an example of (a) acidic oxide (b) basic oxide (c) neutral oxide (d) mixed oxide

72.Which colour is imparted to the glass by using manganese oxide? (a) Purple (b) Black (c) Blue (d) Green

73.NaAlO2\mathrm{NaAlO_{2}}NaAlO2​ is the molecular formula of : (a) Sodium alumina oxide (b) Sodium meta-aluminate (c) Sodium alumina (d) none of the above

74.Which of the following statement is correct? (a) Na is more reactive than li due to more electron (b) Both a and b (c) F is more reactive because it is metal (d) None of the above

75."KCl and O2\mathrm{O_{2}}O2​ are formed by heating KClO3\mathrm{KClO_{3}}KClO3​", what type of chemical reaction is this (a) Neutralization (b) Single displacement (c) Decomposition (d) Combination

76.Pick out weak acid from the following (a) HNO3\mathrm{HNO_{3}}HNO3​ (b) CH3COOH\mathrm{CH_{3}COOH}CH3​COOH (c) H2SO4\mathrm{H_{2}SO_{4}}H2​SO4​ (d) HCl

77.The reaction from NaOH and CH3COOH\mathrm{CH_{3}COOH}CH3​COOH gives (a) Basic Salt (b) Acidic Salt (c) Normal Salt (d) Neutral Salt

78.The molecular formula of sodium thiosulphate is, (a) Na2S2O2\mathrm{Na_{2}S_{2}O_{2}}Na2​S2​O2​ (b) Na2S4O6\mathrm{Na_{2}S_{4}O_{6}}Na2​S4​O6​ (c) Na2SO4\mathrm{Na_{2}SO_{4}}Na2​SO4​ (d) Na2S2O3\mathrm{Na_{2}S_{2}O_{3}}Na2​S2​O3​

The reaction between strong acid and weak base gives: (a) acidic salt (b) basic salt (c) neutral salt (d) normal salt

The reaction between strong acid and strong base gives: (a) acidic salt (b) basic salt (c) both a and b (d) Neutral salt

ZnO is an example of: (a) amphoteric oxide (b) acidic oxide (c) neutral oxide (d) basic oxide

The Nature of ZnO is (a) acidic (b) basic (c) amphoteric (d) neutral 0 0

Which color is imparted to the glass by using cuprous oxide? (a) Black (b) Purple (c) Red (d) Green

The slaked lime is: (a) $\mathrm{MgCl_{2}}$ (b) CaO (c) $\mathrm{Ca(OH)_{2}}$ (d) $\mathrm{Mg(OH)_{2}}$

What is the colour of blue litmus paper in acidic solution? (a) red (b) blue (c) yellow (d) colourless

Which metal can be extracted from bauxite? (a) Fe (b) Zn (c) Al (d) Cu

Which of the following statement is correct? (a) Na is more reactive than K (b) Ca is less reactive than Mg (c) O has larger atomic size than S (d) none of the above

What is the pH value of products of neutralization reaction? (a) 5 (b) 6 (c) 7 (d) 8

What is the molecular weight of $\mathrm{Na_{2}SO_{4}}$ ? (a) 140 (b) 141 (c) 142 (d) 143

– COOH is the functional group of : (a) alcohol (b) ether (c) aldehyde (d) carboxylic acid

The reaction between ammonia and carbon dioxide gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) none of these

$\mathrm{CuSO_4\cdot 5H_2O}$ is the molecular formula of: (a) green vitriol (b) blue vitriol (c) white vitriol (d) none of these

Which colour get imparted in the glass by using chromium oxide? (a) Black (b) Blue (c) Green (d) Yellow

The thick paste of cement and sand in the ratio of 1:3 with water is called (a) cement concrete (b) cement clinker (c) cement mortar (d) cement powder

The solution of calcium hydroxide is also called as (a) quick lime (b) slaked lime (c) lime water (d) both 'b' and 'c'

The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A

The position of alkaline earth metal is (a) I A (b) II A (c) III A (d) IV A 6 2

The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) carbonization

The nature of soap is: (a) bio-degradable (b) non-biodegradable (c) easily soluble in hard water (d) none of the above

The number of atoms of oxygen present in the ozone are. (a) 3 (b) 4 (c) 2 (d) 1

In modern periodic table, the elements placed in VIIA are (a) Halogen (b) alkaline earth metal (c) alkali metal (d) inert gas

In the decomposition of limestone, $\mathrm{CaCO_3 \xrightarrow{\Delta} A + CO_2}$ , A is also called as: (a) Lime water (b) Slaked lime (c) quick lime (d) milk of lime

Bauxite is used to extract: (a) Cu (b) Al (c) Fe (d) Zn

Which alkali metal gives golden yellow color to the flame? (a) Na (b) K (c) Rb (d) Fr

In the Haber’s synthesis of ammonia, the ratio of $\mathrm{N_{2}}$ and $\mathrm{H_{2}}$ is (a) 1:1 (b) 1:2 (c) 1:3 (d) 1:4

In which of the following glasses, boric oxide is used? (a) Silica (b) borosilicate (c) water (d) ordinary

−COOH is the functional group of (a) Carboxylic acid (b) Ester (c) alcohol (d) Ketone

Which of the following is basic oxide? (a) $\mathrm{CO_{2}}$ (b) $\mathrm{Na_{2}O}$ (c) MgO (d) both b and c

Which of the following is bio-degradable? (a) plastic (b) detergents (c) pesticides (d) soap

Which of the following statements is not true for plastic waste? (a) Can be used to make compost (b) It lasts for a longer period of time (c) Toxic fumes are produced when burnt (d) All of the above

The electronic configuration of an element is $[\mathrm{Ar}]\,3d^{6}4s^{2}$ . The element is: (a) Fe (b) Cu (c) Mn (d) Cr

The reaction, $\mathrm{AgNO_{3}}$ + NaCl → AgCl + $\mathrm{NaNO_{3}}$ is (a) Neutralization (b) decomposition (c) single displacement (d) double displacement

Galena is the ore of (a) Pb (b) cu (c) Hg (d) Fe

Brass is an alloy of (a) Cu and Zn (b) Cu and Fe (c) Zn and Fe (d) Cu and Mg

The producer gas is (a) $\mathrm{CO + H_2}$ (b) $\mathrm{CO + N_2}$ (c) $\mathrm{CO + O_2}$ (d) $\mathrm{CO + H_2O}$

To impart red color in the glass, the metallic oxide used is (a) Cupric oxide (b) Cuprous Oxide (c) Chromium Oxide (d) Both a and b

In the mortar, the ratio of cement and sand is (a) 1: 1 (b) 1: 2 (c) 1: 3 (d) 1: 4

Which of the following element is tetravalent? (a) Na (b) C (c) Al (d) K

The milk of magnesia is (a) $\mathrm{Mg(OH)_{2}}$ (b) $\mathrm{MgSO_{4}}$ (c) $\mathrm{MgCl_{2}}$ (d) MgO

Glycerol is also called as: (a) phenol (b) methanol (c) glycerine (d) glycol

The water soluble basic gas is (a) $\mathrm{CO_{2}}$ (b) $\mathrm{H_{2}}$ (c) $\mathrm{NH_{3}}$ (d) $\mathrm{N_{2}}$

Lead crystal glass is made by adding (a) lead monoxide (b) lead peroxide (c) lead super oxide (d) both a and b

The functional group of Carboxylic acid is ? (a) −OH (b) −CHO (c) −COOH (d) −CN

$\mathrm{Na_{2}CO_{3}}$ is an example of (a) Acidic salt (b) basic salt (c) Neutral salt (d) Normal salt

MgO and $\mathrm{Na_{2}}$ O are example of (a) acidic oxide (b) Neutral Oxide (c) Basic Oxide (d) Peroxide

Ant bite contain (a) citric acid (b) formic acid (c) acetic acid (d) lactic acid

Baking powder is prepared from (a) $\mathrm{Na_{2}Co_{3}}$ (b) NaOH (c) $\mathrm{NaHCO_{3}}$ (d) NAcl

Hematite is the ore of (a) Fe (b) Cu (c) pb (d) Al

Which of the following is not alkali metal? (a) Na (b) Ca (c) K (d) Fr

The chief ore to extract the copper is (a) Copper pyrite (b) Cuprite (c) azurite (d) malachite

How many isotopes does Hydrogen have? (a) 1 (b) 2 (c) 3 (d) 4

Which is the most abundant metal in the earth crust? (a) Al (b) Fe (c) Cu (d) Pb

Isotopes have the same (a) atomic number (b) mass no. and atomic no. (c) neutron number (d) mass number

Mercury is extracted from (a) cinnabar (b) haematite (c) bauxite (d) cuprite

The molecular formula of slaked lime is, (a) CaO (b) $\mathrm{Ca(OH)_{2}}$ (c) $\mathrm{Mg(OH)_{2}}$ (d) MgO

Which of the following is an amphoteric oxide? (a) $\mathrm{CO_{2}}$ (b) NO (c) $\mathrm{NO_{2}}$ (d) ZnO

The reaction between ammonia and $\mathrm{CO_{2}}$ gas gives: (a) urea (b) dry ice (c) liquor ammonia (d) ammonium sulphate

Which acid is found in Coca-Cola? (a) Sulphuric acid (b) Nitric acid (c) Formic acid (d) Carbonic acid

Dry ice is formed by cooling (a) $\mathrm{CO_{2}}$ gas (b) $\mathrm{O_{2}}$ gas (c) $\mathrm{N_{2}}$ gas (d) $\mathrm{SO_{2}}$ gas

The molecular formula of Gypsum is (a) $\mathrm{CaSO_4\cdot\frac{1}{2}H_2O}$ (b) $\mathrm{CaSO_4\cdot H_2O}$ (c) $\mathrm{CaSO_4\cdot 2H_2O}$ (d) $\mathrm{CaSO_4\cdot 3H_2O}$

Which of the following is an organophosphrus insecticide? (a) DDT (b) BHC (c) Baygon (d) Malathion

$\mathrm{MgSO_4\cdot 7H_2O}$ is the molecular formula of (a) common salt (b) gypsum salt (c) terrous salt (d) epsom salt

The molecular weight of $\mathrm{K_{2}SO_{4}}$ is (a) 171 (b) 172 (c) 173 (d) 174

CnH2n+2 is the molecular formula of , (a) saturated hydrocarbon (b) alkene (c) alkyne (d) alcohol

Silver metal can be extracted from (a) haematite (b) argentite (c) chalcopyrite (d) bauxite

Which of the following is trihydric alcohol? (a) methanol (b) ethanol (c) propanol (d) glycerol

CnH2n-2 is the general formula of (a) alkane (b) alkene (c) alkyne (d) alcohol

$\mathrm{Fe_{3}O_{4}}$ is an example of (a) acidic oxide (b) basic oxide (c) neutral oxide (d) mixed oxide

Which colour is imparted to the glass by using manganese oxide? (a) Purple (b) Black (c) Blue (d) Green

$\mathrm{NaAlO_{2}}$ is the molecular formula of : (a) Sodium alumina oxide (b) Sodium meta-aluminate (c) Sodium alumina (d) none of the above

Which of the following statement is correct? (a) Na is more reactive than li due to more electron (b) Both a and b (c) F is more reactive because it is metal (d) None of the above

"KCl and $\mathrm{O_{2}}$ are formed by heating $\mathrm{KClO_{3}}$ ", what type of chemical reaction is this (a) Neutralization (b) Single displacement (c) Decomposition (d) Combination

Pick out weak acid from the following (a) $\mathrm{HNO_{3}}$ (b) $\mathrm{CH_{3}COOH}$ (c) $\mathrm{H_{2}SO_{4}}$ (d) HCl

The reaction from NaOH and $\mathrm{CH_{3}COOH}$ gives (a) Basic Salt (b) Acidic Salt (c) Normal Salt (d) Neutral Salt

The molecular formula of sodium thiosulphate is, (a) $\mathrm{Na_{2}S_{2}O_{2}}$ (b) $\mathrm{Na_{2}S_{4}O_{6}}$ (c) $\mathrm{Na_{2}SO_{4}}$ (d) $\mathrm{Na_{2}S_{2}O_{3}}$