Answer to Question #316793 in General Chemistry for Ali

Question

b) If 15.0 grams of calcium hydroxide is combined with 75.0 mL of 0.500 M HCl, how many grams of calcium chloride would be formed?

Answer 1

Balanced equation :

Ca(OH)2(aq) + 2HCl(aq) → CaCl2(aq) + 2H2O(l)

1 mol Ca(OH)2 react6s with 2 mol HCl

Molar mass Ca(OH)2 = 74.09 g/mol

Mol Ca(OH)2 in 15.0 g = 15.0 g / 74.09 g/mol = 0.202 mol

This will react with 0.202 mol * 2 = 0.404 mol HCl

Mol HCl in 75 mL of 0.500 M HCl solution:

mol HCl = 75 mL / 1000 mL/L * 0.5 mol /L = 0.03750 mol HCl

You do not have sufficient HCl to react with all the Ca(OH)2 The HCl is limiting

The simple answer is that no calcium hydroxide is formed

But If I assume that you really want to ask :

What mass of CaCl2 was produced

From the equation

0.03750 mol HCl will produce 0.03750 /2 = 0.01875 mol CaCl2

Molar mass CaCl2 = 40.0 + 35.5*2 = 111 g/mol

Mass of 0.01875 mol CaCl2 = 0.01875 mol * 111 g/mol = 2.08 g

Answer: 2.08 g CaCl2 will be produced