chemistry problem

Question

You carefully weigh out 12.00 g of CaCO3 powder and add it to 48.60 g of HCl solution. You notice bubbles as a reaction takes place. You then weigh the resulting solution and find that it has a mass of 55.68 g . The relevant equation is

CaCO3(s)+2HCl(aq)→H2O(l)+CO2(g)+CaCl2(aq)

Assuming no other reactions take place, what mass of CO2 was produced in this reaction?

please I don't get it

Answer 1

CaCO₃(s) + 2HCl(aq) → H₂O(l) + CO₂(g) + CaCl (aq) ... balanced equation

This problem is an example of the concept of Conservation of Mass. The mass of the products must be the same as the mass of the reactants, since mass cannot be created nor destroyed.

Mass of reactants = 12.00 g + 48.60 g = 60.60 g

Mass of products = 55.68 g

Difference = 60.60 g - 55.68 g = 4.92 g

This must be the mass of CO₂(g) which, because it is a gas, must have escaped from the reaction vessel and thus was not included in the final weight.