Question

A certain sample of cuprous sulphide is found to have composition ${Cu}_{1.8}S$ because of incorporation of ${Cu}^{2+}$ ions in the lattice. What is the mole percentage of ${Cu}^{2+}$ in total copper content in this crystal?

• A. $99.8\%$
• B. $11.11\%$
• C. $88.88\%$
• D. None of the above

Answer 1

The correct option is B $11.11\%$

Two ${Cu}^{+}$ replaced by one ${Cu}^{2+}$ in $C{u}_{2}S$ sample.
Total loss of Cu $=$ 0.2 mole
$\therefore$ % of ${Cu}^{2+}$ in total copper content = $\frac{0.2}{1.8}\times 100=11.11$