Question

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

4N2 + 502 --> 2N2O5
a) 158.3 grams
b) 38.64 grams
c) 4.96 grams
d) 16.34 grams

Answer 1

Answer: d) 16.34 grams

Step-by-step explanation:

To calculate the moles :

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

`\text{Moles of} N_2O_5=(31.5g)/(108.01g/mol)=0.292moles`

The balanced chemical reaction given is:

`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= =
`(4)/(2)* 0.292=0.584moles` of
`N_2`

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

Thus 16.34 g of
`N_2` will be needed