When electric current is passed through dilute acidified water, 112 mL of hydrogen gas (measured at STP) is collected at the cathode in 965 seconds. The current (in amperes) that was passed is:

Correct answer: 1.0

Solution

112 mL at STP = 0.112/22.4 = 0.005 mol H2. Each H2 needs 2 electrons, so 0.01 mol electrons = 0.01*96500 = 965 C. I = 965/965 = 1.0 A.

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