When dinitrogen pentoxide comes in contact with water, nitric acid is produced according to the equation below. How many grams of dinitrogen pentoxide were required to produce 37.18 grams of nitric acid?

[tex]\[ \text{? } N_2O_5 + \text{? } H_2O \longrightarrow \text{? } HNO_3 \][/tex]



Answer :

To determine how many grams of dinitrogen pentoxide (N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex]) are required to produce 37.18 grams of nitric acid (HNO[tex]\(_3\)[/tex]), we will follow a step-by-step approach:

1. Determine the molar masses:
- The molar mass of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex] is 108.01 g/mol.
- The molar mass of HNO[tex]\(_3\)[/tex] is 63.01 g/mol.

2. Calculate the number of moles of HNO[tex]\(_3\)[/tex] produced:
- We start with 37.18 grams of HNO[tex]\(_3\)[/tex].
- To find the number of moles, use the formula:
[tex]\[ \text{moles of HNO}_3 = \frac{\text{mass of HNO}_3}{\text{molar mass of HNO}_3} \][/tex]
Substituting the given values:
[tex]\[ \text{moles of HNO}_3 = \frac{37.18 \, \text{g}}{63.01 \, \text{g/mol}} \approx 0.5901 \, \text{mol} \][/tex]

3. Relate moles of HNO[tex]\(_3\)[/tex] to moles of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex]:
- According to the balanced chemical equation, 1 mole of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex] produces 2 moles of HNO[tex]\(_3\)[/tex].
- Thus, to find the moles of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex] required, we divide the moles of HNO[tex]\(_3\)[/tex] by 2:
[tex]\[ \text{moles of N}_2\text{O}_5 = \frac{\text{moles of HNO}_3}{2} \][/tex]
Substituting the calculated moles of HNO[tex]\(_3\)[/tex]:
[tex]\[ \text{moles of N}_2\text{O}_5 = \frac{0.5901 \, \text{mol}}{2} \approx 0.2950 \, \text{mol} \][/tex]

4. Calculate the required mass of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex]:
- To find the mass of N[tex]\(_2\)[/tex]O[tex]\(_5\)[/tex], use the formula:
[tex]\[ \text{mass of N}_2\text{O}_5 = \text{moles of N}_2\text{O}_5 \times \text{molar mass of N}_2\text{O}_5 \][/tex]
Substituting the values:
[tex]\[ \text{mass of N}_2\text{O}_5 = 0.2950 \, \text{mol} \times 108.01 \, \text{g/mol} \approx 31.87 \, \text{g} \][/tex]

Therefore, 31.87 grams of dinitrogen pentoxide are required to produce 37.18 grams of nitric acid.