Question

How many atoms of calcium will be deposited from a solution of $CaC{l}_2$ by a current of $25mA$ flowing for $60$ seconds?

• A. $4.68\times 10^{18}$
• B. $4.68\times 10^{15}$
• C. $4.68\times 10^{12}$
• D. $4.68\times 10^9$

Answer 1

Answer: (A)

Quantity of electricity passed $=\frac{25}{1000}\times 60=1.5C$

$2F=2\times 96500C$ will deposit $1moleCa$

$\therefore 1.5C\text{ will deposit }Ca=\left(\frac{1}{2\times 96500}\times 1.5\right)mole$

$=\frac{1}{2\times 96500}\times 1.5\times 6.023\times 10^{23}\text{ atom }=4.68\times 10^{18}$