Question

Salts of A (atomic mass 15), B (atomic mass 27) and C (atomic mass 48) were electrolyzed using the same amount of charge. It was found that when 4.5 g of A was deposited, the masses of B and C deposited were 2.7 g and 9.6 g. The valences of A, B and C were respectively

• A. 1, 3 and 2
• B. 3, 1 and 3
• C. 3,1 and 2
• D. 2,3 and 2

Answer 1

The correct option is C

3,1 and 2

According to Faraday's Second Law :

$\frac{MassofA}{EquivalentmassofA}=\frac{MassofB}{EquivalentmassofB}=\frac{MassofC}{EquivalentmassofC}$
$\frac{4.5}{\frac{15}{n_1}}=\frac{2.7}{\frac{27}{n_2}}=\frac{9.6}{\frac{48}{n_3}}$

$\begin{array}{ccccc}{n}_1& :& n_2& :& n_3\\ 0.3& :& 0.1& :& 0.2\\ 3& :& 1& :& 2\end{array}$