Question

The charge required to deposit $9g$ of $Al$ from an $A{l}^{3+}$ solution is:

• A. $32166.3C$
• B. $96500C$
• C. $3216.33C$
• D. $9650C$

Answer 1

The correct option is B $96500C$

$A{l}^{3+}+3e^{-}\to Al$

The atomic mass of $Al=27$ g/mol

$9g$ of $Al=\frac{9}{27}=0.333$ moles

$1$ mole Al$=$ $3$ moles electrons.

$0.333$ moles $Al=0.333\times 3=1$ mole electrons

$1$ mole electrons $=1$ faraday of electricity $=95000$ C.

Hence, option $\left(B\right)$ is the correct answer.