Question

Find out the volume of gasses evolved by passing 0.965 A current for 1 hr through an aqueous solution of $C{H}_{3}COONa$ at ${25}^{0}C$ and 1 atm:

• A. 0.036 L
• B. 1.76 L
• C. 0.072 L
• D. 1.12 L

Answer 1

Answer: (B)

1.76 L

$2C{H}_{3}COONa\to C{H}_{3}C{H}_3+2e^{-}+2C{O}_2+2N{a}^{+}$

$2H_{2}O+2e^{-}\to H_2+2O{H}^{-}$

$2C{H}_{3}COONa+2H_{2}O\to C{H}_{3}C{H}_3+2C{O}_2+H_2+2NaOH$

Thus 2 moles of electrons will produce 4 moles of gases.

The number of moles of electrons passed are $\frac{it}{96500}=\frac{0.965\times 3600}{96500}=0.036$ moles.

The number of moles of gases produced will be $2\times 0.036=0.072$ moles.

The volume occupied by these gases at ${25}^{o}C$ and 1 atm will be $V=\frac{nRT}{P}=\frac{0.072\times 0.0821\times 298}{1}=1.76$ L.