7D SET 3 vibz

Name the gas evolved [formula is not acceptable] – The gas that can be oxidized to sulphur.

Give the equation for:
Reaction of - sugar with conc. H₂SO₄

Answer explanation

C₁₂H₂₂O₁₁+ nH₂SO₄ ⟶ 12C + 11H₂O

Give a balanced equation for the conversion of zinc oxide to zinc sulphate.

Answer explanation

ZnO + H₂SO₄ [dil.] ⟶ ZnSO₄ + H₂O

Select from A, B, C –The solution which liberates sulphur dioxide gas, from sodium sulphite. ​ ​ ​ (a)  

• B: A weak acid.
• C: Dilute sulphuric acid
• A: Sodium hydroxide solution.

State your observation when – Sugar crystals are added to conc. sulphuric acid.

Answer explanation

Steam is evolved from the test tube and it becomes very hot. Black spongy mass of carbon is formed.

Choose the correct answer from the choices:
The gas evolved when dil. sulphuric acid reacts with iron sulphide.

• A: Hydrogen sulphide

• B: Sulphur dioxide

• C: Sulphur trioxide

• D: Vapour of sulphuric acid.

Give a balanced equation for – Dilute sulphuric acid is poured over sodium sulphite

Answer explanation

Na₂SO₃ + H₂SO₄ (dil.) ⟶ Na₂SO₄ + H₂O + SO₂

Give balanced equations for the manufacture of sulphuric acid by the Contact process. (Mention the different chambers where each step takes place)

Answer explanation

State the property of sulphuric acid shown by the reaction of conc. sulphuric acid when heated with

(a) Potassium nitrate

(b) Carbon

Answer explanation

a) Sulphuric acid behaves as a non volatile acid.

KNO3+H2SO4[conc.]→<200°CKHSO4+HNO3KNO3​+H2​SO4​[conc.]<200°C​KHSO4​+HNO3​

(b) Sulphuric acid behaves as an oxidizing agent

C + 2H₂SO₄ ⟶ CO₂ + 2H₂O + 2SO₂

State one appropriate observation for : conc. H₂SO₄ is added to a crystal of hydrated copper sulphate.

Answer explanation

The blue coloured hydrous copper sulphate changes to white anhydrous copper sulphate as the water of crystallization is removed.