You weigh out 1.20 g of sodium carbonate monohydrate, dissolve it in water and react it with 15.00 mL of 2.00 M HCl. Write an equation for the reaction and calculate the expected mass of carbon dioxide that will be produced.

Answer 1

This is a limiting reagent problem. I know that because amounts are given for BOTH reactants.
Na2CO3 + 2HCl ==> H2O + CO2 + 2NaCl

mols Na2CO3 = grams/molar mass = ?
mols HCl = m x L = ?
Convert mols Na2CO3 to mols CO2. use the coefficients in the balanced equation to do this.
Convert mols HCl to mols CO2 the same way.
It is likely that the mols from these steps will not agree and one of them must not be right. The correct answer in limiting reagent problems is ALWAYS the smaller value and the reagent producing that value is the limiting reagent.
Use the smaller value and convert to grams CO2. g = mols x molar mass.