Question

in the commercial manufacture of nitric acid, how many liters of nitrogen dioxide will produce 30 liters of nitric oxide given that both gases are at stp?

Answer 1

3NO2 + H2O = 2HNO3 + NO

moles of nitric oxide:
under STP (Standard Tempreture and Pressure) 
22.4L of any gas = 1mole

so 30L of NO: 30 / 22.4 = 1.33928571429 moles

so you use the ratios 3:1 to find the moles of the nitrogen dioxide: 1.33928571429 x 3 (is the ratio) =4.01785714286mol⁻¹ of NO₂

now to find liters use: L = Moles x 22.4
L of NO₂ = 90L

hope that helps 

Answer 2

Answer: The volume of nitrogen dioxide needed to produce given amount of nitric acid is 45 L.

Explanation:

At STP:

1 mole of a gas occupies 22.4 L of volume.

The chemical equation for the manufacturing of nitric acid is given as:

$3NO_2+H_2O\rightarrow 2HNO_3+NO$

By Stoichiometry of the reaction:

$(2\times 22.4)=44.8L$ of nitric acid is produced from $(3\times 22.4)=67.2L$ of nitrogen dioxide.

So, 30 L of nitric acid will be produced from = $\frac{67.2L}{44.8L}\times 30L=45L$ of nitrogen dioxide.

Hence, the volume of nitrogen dioxide needed to produce given amount of nitric acid is 45 L.