Question

what is the total mass of CaO that reacts with completely with 88 grams of CO2 to produce 200 grams of CaCO3 How do you calculate this?

Answer 1

We can just use the law of conservation of mass. Recall that this states that mass can neither be created nor destroyed.

In this case we have two reactants reacting to produce a single product. \[X+Y \rightarrow Z\]

If we have 10 grams of reactant X and 10 grams of reactant Y, then we will produce 20 grams of product Z.

Answer 2

CaO + CO2 = CaCO3

Since both sides have the same number of Ca, C, and O atoms, the equation is balanced. One mole of CaO and one of CO2 will produce one of CaCO3

@Eashmore is right: the total output mass must equal the total input mass, and you need not worry about number of moles. [Nor mice.]