# How many molecules in a HALF-MOLAR quantity of N_2O_5?

Number of moles of ${N}_{2} {O}_{5} = \frac{1}{2} \cdot m o l .$........And
Number of moleculess of ${N}_{2} {O}_{5} = \ldots \ldots . .$
$= \text{Mass"/"Molar Mass"xx"Avogadro's number}$
$= \frac{54 \cdot g}{108.01 \cdot g \cdot m o {l}^{-} 1} \times 6.022 \times {10}^{23} \cdot m o {l}^{-} 1 = 3.01 \times {10}^{23} \cdot \text{molecules}$.