Chemistry help!!!

Question

Nitrogen dioxide (NO2) is a pollutant that is primarily removed from the atmosphere by reaction with hydroxyl radicals (OH) to form nitric acid (HNO3). 

NO2(g)+OH(g)⟶HNO3(aq)

How many grams of nitric acid are produced from this reaction if it reduces the partial pressure of NO2 from a 1.3×109L volume of air over a city by 4.5×10−8atm when the temperature is 10∘C?

Answer 1

NO₂(g) + OH(g)⟶HNO₃(aq) ... balanced equation

∆ PNO₂ = 4.5x10^-8 atm

volume = 1.3x10⁹ L

temp = 10ºC + 273 = 283K

moles NO₂ = ? = n

PV = nRT

n = PV/RT = (4.5x10^-8 atm)(1.3x10⁹ L) / (0.0821 Latm/Kmol)(210K)

n = 3.4x10^-18 moles NO₂ = mols HNO₃

mass HNO₃ = 3.4x10^-18 moles x 31 g/mol = 1.05x10^-16 g