Question

Assertion (A): In the electrolysis of acidified water, the volume of hydrogen liberated is twice the volume of oxygen formed.
Reason (R): Water has hydrogen and oxygen in the ratio of 1:2 by volume.

• A. (A) is true but (R) is false.
• B. (A) is false but (R) is true.
• C. Both (A) and (R) are true and (R) is the correct explanation of (A).
• D. Both (A) and (R) are true, but (R) is not the correct explanation of (A).

Hint:

In a Hoffmann voltameter, the level of water in the cathode limb (where H_2 collects) will be twice as low as the level in the anode limb (where O_2 collects)!

Answer 1

The Correct Option is A

Step 1: Understanding Water Electrolysis: 
The decomposition of water into its constituent gases is represented by the equation: [ 2H_2O (l) 2H_2 (g) + O_2 (g) ] 

Step 2: Evaluating the Assertion: 
From the balanced equation, 2 volumes of Hydrogen are produced for every 1 volume of Oxygen. Thus, Assertion (A) is True. 

Step 3: Evaluating the Reason: 
Water (H_2O) consists of Hydrogen and Oxygen in a ratio of 2:1 by volume (and 1:8 by mass). Reason (R) states the ratio is 1:2, which is False. 

Step 4: Final Answer: 
Assertion (A) is true but Reason (R) is false.