Question

What mass of N2 will be needed to produce 31.5 grams of N2O5?

Answer 1

Answer: d) 16.34 grams

Explanation:

To calculate the moles :

$\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}$  

$\text{Moles of} N_2O_5=\frac{31.5g}{108.01g/mol}=0.292moles$

$4N_2+5O_2\rightarrow 2N_2O_5$  

According to stoichiometry :

As 2 moles of $N_2O_5$ are produced by= 4 moles of $N_2$

Thus 0.292 moles of $N_2O_5$ are produced by=  =$\frac{4}{2}\times 0.292=0.584moles$ of $N_2$

Mass of $N_2=moles\times {\text {Molar mass}}=0.584moles\times 28g/mol=16.34g$

Thus 16.34 g of $N_2$ will be needed