Question

A $100.0\, mL$ dilute solution of $Ag ^{+}$is electrolysed for $15.0$ minutes with a current of $1.25 \,mA$ and the silver is removed completely. What was the initial $\left[ Ag ^{+}\right]$?

• A. $2.32 \times 10^{-1}$
• B. $2.32 \times 10^{-4}$
• C. $2.32 \times 10^{-3}$
• D. $1.16 \times 10^{-5}$

Answer 1

Answer: (D)

No. of moles of
$A g^{+}=\frac{15 \times 60+1.25 \times 10^{-3}}{96,500} \times \frac{1}{1}$
$=0.0116 \times 10^{-3}$
$\therefore \left[A g^{+}\right]=\frac{1.16 \times 10^{-5}}{\frac{100}{1000}}$
$=1.16 \times 10^{-4}$