Question

Suppose 1 gram of Li2CO3 is reacted with in 50.0 mL of 3.00 M HCl. What would be the mass of CO2 liberated in the reaction? After the reaction, how many moles of HCl are left over?

Answer 1

This is a limiting reagent problem.

Another worked example.
http://www.jiskha.com/science/chemistry/limiting_reagent_problem.html