Question

A constant current of $30A$ is passed through an aqueous solution of $NaCl$ for a time of $1.00h$. What is the volume of $C{l}_2$ gas at STP produced?

• A. 30.00 L
• B. 25.08 L
• C. 12.54 L
• D. 1.12 L

Answer 1

Answer: (C)

Due to electrolysis
$2H_{2}O\left(l\right)+2e^{-}\to H_2\left(g\right)+2O{H}^{-}\left(aq\right)$
$\frac{2C{l}^{-}\left(aq\right)\to C{l}_2\left(g\right)+2e^{-}}{2H_{2}O\left(l\right)+2C{l}^{-}\left(aq\right)\to H_2\left(g\right)+C{l}_2\left(g\right)+2O{H}_{\left(aq\right)}^{-}}$
$\frac{}{O{H}^{-}formed=NaOHformed=Zit}$
$=\frac{E}{96500}\times i\times 1$
$=\frac{40}{96500}\times 30\times 1\times 60\times 60=44.77g$
$=\frac{44.77}{40}=1.12mol$
$C{l}_2$ formed = $\frac{1}{2}$ mol of $NaOH$
$=\frac{1.12}{2}=.056$ mol
$=0.56\times 22.4L$ at $STP=12.54L$