If 1.49 grams of NO react, how many grams of NO2 form?

Question

Consider the following balanced reaction.

2H⁺ (aq) + 2NO₃^- (aq) + NO (g)  3NO₂ (g) + H₂O (l)

Answer 1

This is a problem in stoichiometry and in using dimensional analysis.

2H⁺ (aq) + 2NO₃^- (aq) + NO (g)  3NO₂ (g) + H₂O (l) ... balanced equation

From the balanced equation, we see that the stoichiometry is 1 mol NO produces 3 mols NO₂. We will use this relationship to find grams of NO₂ formed from 1.49 grams of NO.

First, convert to moles:

moles NO used = 1.49 g NO x 1 mol NO/30.0 g = 0.0497 moles NO

Find moles NO₂ produced:

0.0497 mols NO x 3 mols NO₂/mol NO = 0.149 moles NO₂ produced

Finally convert to grams:

0.149 moles NO₂ x 46 g/mol = 6.85 g NO₂ produced