Question

The number of unit cells in $58.5g$ of $NaCl$ is nearly.

• A. $6 \times 10^{20}$
• B. $3 \times 10^{22}$
• C. $1.5 \times 10^{23}$
• D. $0.5 \times 10^{24}$

Answer 1

Answer: (C)

$1.5 \times 10^{23}$

Answer 2

$58.5gNaCl = 1mole = 6.02 \times 10^{23}Na^{+}Cl^{-}units$.

One unit cell contains $4Na^{+}Cl^{-}$ units. Hence number of unit cell present $= \frac{6.02 \times 10^{23}}{4} = 1.5 \times 10^{23}$.