Sulphuric Acid | Study of Compounds | Previous year Questions | Class 10 | ICSE Chemistry

Sulphuric Acid

Q1. Choose the correct answer from the options given below:

(i) When dilute sulphuric acid reacts with iron sulphide, the gas evolved is: [2011][1]

a.      Hydrogen sulphide

b.      Sulphur dioxide

c.      Sulphur trioxide

d.      Vapour of Sulphuric acid

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Ans. a. Hydrogen sulphide

(ii) In the given equation, identify the role played by conc. sulphuric acid. [2013][1]
S +2H₂SO₄ ----> 3SO₂ + 2H₂O

a.      Non- volatile acid

b.      Oxidising agent

c.      Dehydrating agent

d.      none of the above

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Ans. b. Oxidising agent

(iii) The catalyst used in Contact Process is: [2018][1]

a.      Copper

b.      Iron

c.      Vanadium pentoxide

d.      Manganese dioxide

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Ans. c. Vanadium pentoxide

(iv) The acid which can produce carbon from cane sugar is: [2020][1]

a.      Concentrated Hydrochloric acid

b.      Concentrated Nitric acid

c.      Concentrated Sulphuric acid

d.      Concentrated Acetic acid

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Ans. c. concentrated Sulphuric acid

(v) The acid which is least volatile is: [2022][1]

a.      Hydrochloric acid

b.      Nitric acid

c.      Dilute sulphuric acid

d.      Concentrated sulphuric acid

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Ans. d. Concentrated sulphuric acid

(vi) Vanadium pentoxide is used as a catalyst in the preparation of: [2022][1]

a.      Nitrogen gas

b.      Nitrogen dioxide gas

c.      Sulphur trioxide gas

d.      Carbon dioxide gas

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Ans. c. Sulphur trioxide gas

(vii) The gas formed when carbon reacts with concentrated sulphuric acid: [Specimen 2023]

a.      Hydrogen

b.      Sulphur trioxide

c.      Sulphur dioxide

d.      Oxygen

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Ans. c. Sulphur dioxide

 

Q2. Name the following:

(i) An aqueous salt solution used for testing sulphate radical. [2011][1]

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Ans. Barium chloride

(ii) The gas produced on reaction of dilute Sulphuric acid with a metallic sulphide. [2012][1]

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Ans. Hydrogen sulphide gas

(iii) A dilute mineral acid which forms a white precipitate when treated with barium chloride solution. [2013][1]

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Ans. Dilute Sulphuric acid

(iv) The acid which is used in the preparation of a non-volatile acid. [2015][1]

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Ans. concentrated nitric acid

(v) The acid which produces sugar charcoal from sugar. [2015][1]

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Ans. Conc. sulphuric acid

(vi) The acid which on mixing with lead nitrate solution produces a white precipitate which is insoluble even on heating. [2015][1]

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Ans. Dil. sulphuric acid

(vii) The acid that is a dehydrating as well as a drying agent. [2020][1]

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Ans. Conc. Sulphuric acid

(viii) A substance added to water, to manufacture sulphuric acid in Contact process. [2022][1]

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Ans. Oleum

Q3. What do you observe in each of the following cases?

(i) Sugar crystals are added to a hard glass test tube containing concentrated sulphuric acid. [2011][2016][1]

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Ans. Sugar crystals get charred and turn into a black spongy mass.

(ii) Concentrated Sulphuric acid is added dropwise to a crystal of hydrated copper sulphate. [2013][2017][1]

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Ans. Blue crystals turn into white amorphous powder.

(iii) Barium chloride solution is mixed with sodium sulphate solution. [2016][2018][1]

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Ans. A white ppt. of barium sulphate is formed.

Q4. Write the balanced chemical equation for each of the following reactions:

(i) Dilute Sulphuric acid is poured over sodium sulphite. [2011][2016][1]

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Ans. Na₂SO₃ + H₂SO₄ -----------> Na₂SO₄ + H₂O + SO₂↑

(ii) Zinc sulphide and dilute sulphuric acid. [2012][1]

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Ans. ZnS + H₂SO₄ ---------> ZnSO₄ + H₂S↑

(iii) Dehydrating property of concentrated Sulphuric acid with sugar crystals. [2013][2017][1]

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Ans. C₁₂H₂₂O₁₁ ---^{conc. H}₂^SO₄ ---> 12C +11H₂O

(iv) Action of concentrated sulphuric acid on carbon. [2014][2017][2018][1]

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Ans. C +2H₂SO₄ ----> CO₂ + 2SO₂↑ +2H₂O

(v) Action of sulphuric acid on potassium hydrogen carbonate. [2015][1]

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Ans. 2KHCO₃ + H₂SO₄ ------> K₂SO₄ + 2H₂O + 2CO₂

(vi) Action of sulphuric acid on sulphur. [2015][2017][1]

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Ans. S +2H₂SO₄ ----> 3SO₂↑ + 2H₂O

(vii) The behaviour of H₂SO₄ as an acid when it reacts with magnesium. [2017][1]

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Ans. Mg + H₂SO₄ --------> MgSO₄ + H₂↑

(viii) Action of dilute sulphuric acid on sodium hydroxide. [2019][1]

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Ans. 2NaOH +H₂SO₄ ---> Na₂SO₄ +2H₂O

(ix) Action of dilute sulphuric acid on zinc sulphide. [2019][1]

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Ans. ZnS + H₂SO₄-----> ZnSO₄ + H₂S↑

 

Q5. With the help of equations, give an outline for the manufacture of Sulphuric acid by the contact process. [3][2011]

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Ans. S + O₂ ----> SO₂

2SO₂ + O₂ –---V₂O₅/Pt 400-450°C----> 2SO₃

SO₃ + H₂SO₄ ------> H₂S₂O₇

H₂S₂O₇ + H₂O -------> 2H₂SO₄

Q6. In the contact process for the manufacture of sulphuric acid give the equations for the conversion of sulphur trioxide to sulphuric acid. [2015][2017][2]

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Ans.

SO₃ + H₂SO₄ ------> H₂S₂O₇

H₂S₂O₇ + H₂O -------> 2H₂SO₄

Q7. What property of Sulphuric acid is shown in the reaction of concentrated Sulphuric acid when heated with

(A)             Potassium nitrate

(B)             Carbon ? [2011][2]

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Ans.

 (A) Non-volatile nature

(B) Oxidising property

Q8. Some properties of Sulphuric acid are listed below. Choose the role played by Sulphuric acid as A, B, C or D which is responsible for the reactions (i) to (v). Some role(s) may be repeated. [5][2012] [Specimen 2023]

(A) Dilute acid

(B) Dehydrating agent

(C) Non-volatile acid

(D) Oxidising agent

(i) CuSO₄.5H₂O ------Conc. H₂SO₄-------> CuSO₄ + 5H₂O

(ii) S + H₂SO₄ (conc.) --------> 3SO₂ + 2H₂O

(iii) NaNO₃ + H₂SO₄ (conc.) -----200°C-----> NaHSO₄ + HCl

(iv) MgO + H₂SO₄ ---------> MgSO₄ + H₂O

(v) Zn + 2H₂SO₄ (conc.) --------> ZnSO₄ + SO₂ + 2H₂O

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Ans.

(i)   (B) Dehydrating agent

(ii) (D) Oxidising agent

(iii) (C) Non-volatile acid

(iv) (A) Dilute acid

(v)  (D) Oxidising agent

 

Q9. Identify the anion present in the following compounds:

(i) Compound Z which on reacting with dilute Sulphuric acid liberates a gas which turns limewater milky, but the gas has no effect on acidified potassium dichromate solution. [2012][2015][1]

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Ans. Carbonate ion (CO₃^2-)

(ii) Compound L on reacting with barium chloride solution gives a white precipitate insoluble in dilute hydrochloric acid or dilute nitric acid. [2012][2015] [Specimen 2023] [1]

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Ans. Suphate ion (SO₄^2-)

Q10. Give one chemical test to differentiate between each of the following pairs:

(i) Sodium carbonate and sodium sulphite [2012][1]

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Ans. When sodium carbonate is treated with dil. H₂SO_­4, brisk effervescence takes place and a colourless, odourless gas is liberated which turns limewater milky but has no effect on acidified potassium dichromate solution. But when sodium sulphite is treated with dil. H₂SO₄, a colourless gas having smell of burning sulphur is formed which turns orange/yellow solution of acidified potassium dichromate green.

(ii) Dilute hydrochloric acid and dilute sulphuric acid. (using lead nitrate solution) [2019][1]

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Ans. On adding lead nitrate solution, if a white precipitate is formed which dissolves on heating, then it is dilute HCl. If the white precipitate formed does not dissolve on heating, then it is dilute H₂SO₄.

Q11. Distinguish between the following pairs of compounds using the test given within brackets:

(i) Sodium nitrate and sodium sulphite (using dilute Sulphuric acid). [2014][1]

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Ans. When sulphuric acid is added to each of the two, no effect takes place with sodium nitrate whereas, with sodium sulphite, a colourless gas SO₂, is formed which has a smell of burning sulphur and turns moist blue litmus paper red.

(ii) Dilute Sulphuric acid and dilute hydrochloric acid (using barium chloride solution). [2014][1]

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Ans. When barium chloride solution is added to each of the acids, a white precipitate of barium sulphate is formed with sulphuric acid whereas no reaction takes place with hydrochloric acid.

(iii) Sodium sulphite solution and sodium sulphate solution. [using dilute H₂SO₄]. [2022][1]

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Ans. On adding dilute H₂SO₄, if no effect takes place, then it is sodium sulphate. On adding dilute H₂SO₄, if a colourless gas SO₂ is formed which has a smell of burning sulphur and turns blue litmus red, then it is sodium sulphite.

 

Q12. State any two conditions for the conversion of sulphur dioxide to sulphur trioxide. [2014][2][Specimen 2023]

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Ans. Vanadium pentoxide is used as catalyst at a temperature of 450°C and 2 atm pressure. 

Q13. State the inference drawn from the following observations:

(i) Salt S is prepared by reacting dilute sulphuric acid with copper oxide. Identify S. [2014][1]

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Ans. Salt S is copper sulphate.

 

Q14. Give one equation each to show the following properties of sulphuric acid: [2014][3]

(i) Dehydrating property

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Ans. CuSO₄.5H₂O ---conc. H₂SO₄---> CuSO₄ + 5H₂O

(ii) Acidic nature

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Ans. 2Na + H₂SO₄ ----> Na₂SO₄ + H₂

(iii) Non- volatile acid

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Ans. NaCl + H₂SO₄  ---less than 200⁰C-->NaHSO₄ +HCl

Q15. Give balanced chemical equation to prepare sodium sulphate using dilute sulphuric acid. [2014][1]

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Ans. 2NaCl + H₂SO₄ --above 200⁰C-----> Na₂SO₄ + 2HCl

Q16. A, B, C and D summarize the properties of sulphuric acid depending on whether it is dilute or concentrated. [2016][3]
A = Typical acid property
B = Non-volatile acid
C = Oxidizing agent
D = Dehydrating agent
Choose the property (A, B, C or D) depending on which is relevant to each of the following:

(i) Preparation of hydrogen chloride gas.

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Ans. B

(ii) Preparation of copper sulphate from copper oxide.

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Ans. A

(iii) Action of conc. sulphuric acid on sulphur.

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Ans. C

Q17. Complete the following by selecting the correct option from the choices given:

(i) The metal which does not react with water or dilute H₂SO₄ but reacts with concentrated H₂SO₄ is ……………… (Al/Cu/Zn/Fe). [2017][1]

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Ans. Cu

Q18. Copy and complete the following table which refers to the industrial method for the preparation of sulphuric acid. [2019][2]

Name of the compound	Name of the process	Catalytic equation (with the catalyst)
Sulphuric acid	(i) ………………	(ii) …………….

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Ans. (i) Contact process

(ii) 2SO₂ + O₂ ----V₂O₅------> 2SO₃

Q19. Write balanced equation for the following conversions:

a. Carbon from cane sugar and concentrated sulphuric acid. [2022][1]

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Ans. C₁₂H₂₂O₁₁ ---^{conc. H}₂^SO₄ ---> 12C +11H₂O

b. Ammonium sulphate from ammonium hydroxide and sulphuric acid. [2022][1]

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Ans. 2NH₄OH + H₂SO₄ ---------> (NH₄)₂SO₄ + 2H₂O

I hope it was useful.