Question

Another component of acid rain is nitric acid, which forms when NO2, also a pollutant, reacts with oxygen and water according to the simplified equation 4NO2(g)+O2(g)+2H2O(l) → 4HNO3(aq) The generation of the electricity used in a medium-sized home produces about 17 kg of NO2 per year. Part A Assuming that there is adequate O2 and H2O, what mass of HNO3, in kg, can form from this amount of NO2 pollutant? Express the mass to two significant figures and include the appropriate units

Answer 1

Answer: The mass of nitric acid produced is 2.3 kg

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$      .....(1)

Given mass of nitrogen dioxide = 17 kg = 1700 g     (Conversion factor:  1 kg = 1000 g)

Molar mass of nitrogen dioxide = 46.0 g/mol

Putting values in equation 1, we get:

$\text{Moles of nitrogen dioxide}=\frac{1700g}{46.0g/mol}=36.96mol$

For the given chemical reaction:

$4NO_2(g)+O_2(g)+2H_2O(l)\rightarrow 4HNO_3(aq.)$

By Stoichiometry of the reaction:

4 moles of nitrogen dioxide produces 4 moles of nitric acid

So, 36.96 moles of nitrogen dioxide will produce = $\frac{4}{4}\times 36.96=36.96mol$ of nitric acid

Now, calculating the mass of nitric acid from equation 1, we get:

Molar mass of nitric acid = 63.01 g/mol

Moles of nitric acid = 36.96 moles

Putting values in equation 1, we get:

$36.96mol=\frac{\text{Mass of nitric acid}}{63.01g/mol}\\\\\text{Mass of nitric acid}=(39.96mol\times 63.01g/mol)=2328.8g$

Converting this into kilograms, we use the conversion factor:

1 kg = 1000 g

So, $2328.8g=2328.8g\times \frac{1kg}{1000g}=2.3288kg=2.3kg$

Hence, the mass of nitric acid produced is 2.3 kg