**Calcium oxide reacts with hydrochloric acid to produce calcium chloride and water.**

**A. Write the balanced equation.**

**B. If 16 moles of calcium oxide is available, how many moles of hydrochloric acid would be needed?**

**C. How many moles of calcium chloride would be made?**

**Answer:**

Given: Calcium oxide reacts with hydrochloric acid to produce calcium chloride and water.

**A.**

Chemical expression for calcium oxide: CaO

Chemical expression for hydrochloric acid: HCl

Chemical expression for calcium chloride: CaCl2

Chemical expression for water: H2O

Calcium oxide reacts with hydrochloric acid to produce calcium chloride and water.

CaO+HCl→CaCl2+H2O

We need to balance out the equation, which means that each element needs to occur the same amount of times on the left and on the right side of the equation.

We note that chloride Cl occurs twice on the right side, but only once on the left side and thus we need to multiply HCl by 2 to obtain two chloride elements:

CaO+2HCl→CaCl2+H2O

We then note that the number of calcium, chloride, oxygen and hydrogen elements is the same on the left and right side of the equation and thus the equation has been balanced out.

**B**. We have 16 moles of calcium oxide CaO available.

We note that the coefficient of calcium oxide CaO in the balanced equation is 1, while the coefficient of hydrochloric acid HCl is 2. This means that twice as much hydrochloric acid HCl is needed compared to the amount of calcium oxide CaO.

Number of moles of hydrochloric acid HCl:

2×16 moles=32moles.

**C.**

We have 16 moles of calcium oxide CaO available.

We note that the coefficient of calcium oxide CaO in the balanced equation is 1, while the coefficient of calcium chloride CaCl2 is also 1. This means that an equal amount of calcium chloride CaCl2 is made compared to the amount of calcium oxide CaO available.

Number of moles of calcium chloride CaCl2:

1×16 moles=16moles.

**CONCLUSION:**

A. CaO+2HCl→CaCl2+H2O

B. 32 moles

C. 16 moles