Assertion (A): In the Contact Process SO3 gas is not directly dissolved in water to obtain sulphuric acid.
Reason (R): Dense fog or misty droplets of sulphuric acid are formed which is difficult to condense.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(a) Both A and R are true and R is the correct explanation of A.
Explanation:
When sulphur trioxide is brought into direct contact with water,
SO3(g) + H2O(l) ⟶ H2SO4(l)
the reaction is highly exothermic. The heat released vaporises some of the acid and produces a dense fog of minute H2SO4 droplets, which are difficult to condense and collect. Therefore, in the Contact Process the SO3 is first absorbed in concentrated sulphuric acid to form oleum, which is later diluted with water to give the required concentration of H2SO4.
More ICSE Moderate level questions
Which gas decolourises potassium permanganate (KMnO4) solution? (a) Sulphur dioxide (b) Ammonia (c) Hydrogen chloride (d) Carbon dioxide
In the reaction given below sulphuric acid acts as a/an: S + 2H2SO4 ⟶ 3SO2 + 2H2O (a) Non-volatile acid (b) Dibasic acid (c) Oxidising agent (d) Reducing agent
Match the Column A with Column B: Column A Column B (a) N2 + 3H2 ⇌ 2NH3 1. Vanadium Pentoxide (b) 4NH3 + 5O2 ⟶ 4NO + 6H2O 2. Nickel (c) 2SO2 + O2 ⇌ 2SO3 3. Iron (d) C2H4 + H2 ⟶ C2H6 4. Concentrated Sulphuric acid (e) CuSO4.5H2O ⟶ CuSO4 + 5H2O 5. Platinum
Give balanced equations for the following: (a) Action of dilute hydrochloric acid on ammonium carbonate. (b) Oxidation of sulphur with hot concentrated nitric acid. (c) Reaction of concentrated sulphuric acid with carbon.
Differentiate between the following pairs based on the criteria given in the brackets: (a) Cane sugar and hydrated copper sulphate [using concentrated H2SO4] (b) Sulphuric acid and hydrochloric acid [type of salts formed]
Rewrite the following statements by adding the correct word as shown in the example: Example: Given Statement: Ammonia changes moist red litmus to blue. Correct Statement: Aqueous ammonia changes moist red litmus to blue. (a) Sulphuric acid acts as a dehydrating agent. (b) Ammonia reacts with chlorine to give ammonium chloride and nitrogen.
Differentiate between the following pairs based on the criteria given: (a) Sulphuric acid and Nitric acid (using barium chloride solution) (b) Unsaturated and Saturated hydrocarbons (type of bond present)
During the manufacture of sulphuric acid, a chemist collected the gas formed after catalytic oxidation of sulphur dioxide. (a) Name the gas collected. (b) Which acid is formed when the gas collected by the chemist is dissolved directly in water? (c) Why should we not dissolve this gas directly in water?
Complete and balance the following equations: (a) C2H4Br2 + KOH (alcoholic) ⟶ (b) NH3 (excess) + Cl2 ⟶ (c)
The following table is related to an Industrial process of an acid. Name of the process Reactant Catalyst Final product (a) SO2 + O2 (b) (c) Identify (a), (b) and (c).
The reaction between concentrated sulphuric acid and magnesium can be represented by the equation given below: Mg + 2H2SO4 ⟶ MgSO4 + 2H2O + SO2 If 60 g of magnesium is used in the reaction, calculate: (a) mass of acid required. (b) volume of SO2 at STP. [Atomic weights: Mg = 24, H = 1, S = 32, O = 16]
In the reaction S + 2H₂SO₄ → 3SO₂ + 2H₂O, the oxidising agent is: (a) Sulphur (b) Sulphuric acid (c) Sulphur dioxide (d) Water
