Question

When electric current is passed through acidified water, 112 mL of hydrogen gas at STP collected at the cathode in 965 seconds. The current passed in amperes is ______.

Options

• 1.0

• 0.5

• 0.1

• 2.0

Answer 1

When electric current is passed through acidified water, 112 mL of hydrogen gas at STP collected at the cathode in 965 seconds. The current passed in amperes is 1.0.

Explanation:

At cathode:

\[\ce{2H+ (aq) + 2e- -> H2(g)}\]

At NTP, 22.4 L or 22400 mL of H₂ = 1 mol of H₂

112 mL of H₂ 

`=1/22400 xx 112`

= 0.005 mol of H₂

n = `Ixxt/F`

0.005 = `(Ixx965)/(2xx96500)`

`=> I = 1A`