Browse Questions

# A compound is formed by 2 elements M and N. The element N forms ccp and atoms of M occupy a third of tetrahedral voids. What is the formula of the compound?

$\begin{array}{1 1} M_2N_3 \\ MN_3 \\ M_2N \\ MN_6 \end{array}$

Answer: $M_2N_3$
N in ccp $= \large\frac{1}{8} $$\times 8+\large\frac{1}{2}$$\times 6 = 4$
M in tetrahedral voids $= 8 \times \large\frac{1}{3}$$= \large\frac{8}{3} \Rightarrow N:M = 4:\large\frac{8}{3}$$ \rightarrow 3:2$