Question

How many moles of N2O5 are needed to produce 7.90 g of NO2? 2N2O5 = 4NO2 + O2

Answer 1

moles of N2O5 = moles of NO2 * ( 2 moles of N2O5 / 4 moles of NO2

Answer 2

Answer: 0.08585 moles of
`N_2O_5` is needed to produce 7.9 grams of
`NO_2`

Explanation: Moles is calculated by using the formula:

`Moles=\frac{\text{Given mass}}{\text{Molar mass}}`

Molar mass of
`NO_2` = 46 g/mol

Number of moles of
`NO_2=(7.9g)/(46g/mol)` = 0.1717 moles

For the given chemical reaction:

`2N_2O_5\rightarrow 4NO_2+O_2`

By Stoichiometry,

4 moles of
`NO_2` is produced by 2 moles of
`N_2O_5`

So, 0.1717 moles of
`NO_2` is produced by =
`(2)/(4)* 0.1717` = 0.08585 moles of
`N_2O_5`

Hence, moles of
`N_2O_5` is 0.08585 moles.