Question

Acid rain is formed when NO2, a pollutant, reacts with oxygen and rainwater according to the following simplified reaction:

4 NO2 (g) + O2(g) + 2 H2O(l)    4 HNO3(aq)

Assuming that there is more than enough O2 and H2O, how much HNO3 in kilograms forms from 1.5 ✕ 103 kg of NO2.

Answer 1

Sol .

Reaction : 4NO2(g) + O2(g) + 2H2O(l) ---> 4HNO3(aq)

As Mass of NO2 = 1.5 × 10³ Kg = 1.5 × 10³  × 10^-3 g

= 1.5 g

Molar mass of NO2 = 46.00 g/mol

So, Moles of NO2 = Mass of NO2 / Molar mass of NO2

= 1.5 / 46.00   = 0.0326 mol  

Now , From the reaction , 4 moles of NO2 gives 4 moles of HNO3 .

So , 1 mole of NO2 gives = 4/4 = 1 mole of HNO3 .

and , 0.0326 moles of NO2 gives = 1 × 0.0326 = 0.0326 moles of HNO3 .

As Molar mass of HNO3 = 63.01 g/mol  

So , Mass of HNO3 produced = Moles of HNO3 produced × Molar mass of HNO3  

= 0.0326 × 63.01  

= 2.054 g

= 2.054 × 10^-3 Kg

Therefore , answer is 2.054 × 10^-3 Kg