Calculate the no. Of moles of co2 is liberated gives50gm of caco3 reacts with 7.3gm of dil.hcl

This is a limiting reagent (LR) problem.

CaCO3 + 2HCl ==> CaCl2 + H2O + CO2

mols CaCO3 = grams/molar mass = ?
mols HCl = grams/molar mass = ?

Convert mols CaCO3 to mols CO2
Convert mols HCl to mols CO2
You will see that the mols CO2 don't agree; the correct answer in LR problems is ALWAYS the smaller value.