For the reaction 3NO2 + H2O � 2HNO3 + NO, how many grams of HNO3 can form when 1.00 g of NO2 and 2.25 g of H2O are allowed to react?
This is a limiting reagent problem.
1. Write the equation. You have done that and it is balanced.
2. Convert 1.00 g NO2 and 2.25 g H2O to mols.
a. mols NO2 = grams/molar mass = ??
b. mols H2O = grams/molar mass = ??
3. Using the coefficients in the balanced equation, convert mols of what you have (in this case mols NO2 or mols H2O) to mols of what you want (in this case mols HNO3).
3a. using mols NO2 from 2a.
mols HNO3 = mols NO2 x (2 mol HNO3/3 mols NO2) = ??
3b. using mols H2O from 2b.
mols HNO3 = mols H2O x (1 mol H2O/2 mols HNO3) = ??
3c. The smaller of the two answers for HNO3 will be the correct one to use and that is the limiting reagent. The other reagent will be the one that has some material unreacted.
4. Now convert mols of HNO3 to grams HNO3 by
grams HNO3= mols HNO3 x molar mass HNO3.
Post your work if you get stuck.
The above solution assumes the reaction goes to completion from left to right.
2 answers