Question

A sample of $Al{F}_3$ contains $9.036\times {10}^{23}$ $F^{-}$ ions. The volume occupied by the $Al{F}_3$ sample at STP is:

• A. $22.4\text{L}$
• B. $11.35\text{L}$
• C. $5.67\text{L}$
• D. $17.82\text{L}$

Answer 1

The correct option is B $11.35\text{L}$

$3F^{-}$ ions are present in a molecule of $Al{F}_3$.

$\text{The number of molecules of}Al{F}_3\text{that contain}9.036\times {10}^{23}{F}^{-}\text{ions}=\frac{1\times 9.036\times {10}^{23}}{3}$
Therefpre number of moles $Al{F}_3$ $=\frac{1\times 9.036\times {10}^{23}}{3\times 6.023\times {10}^{23}}=0.5\text{mol}$
Volume of $Al{F}_3$ sample occupied at STP $=(0.5\times 22.7)\text{L}=11.35\text{L}$