Question

If i combined 15.0 grams of calcium hydroxide with 75.0 ml of 0.500 m hcl, how many grams of calcium chloride would be formed?

Answer 1

The equation is:
Ca(OH)₂(s) + 2 HCl(aq) → CaCl₂(aq) + 2 H₂O(l)

n=mass in g/M.M

15 g Ca(OH)₂ is n=15 g/ 74.1 g/mol=0.2024 mol of Ca(OH)₂

no. of mol of HCl:

n=0.5 mol/L*0.075L=0.0375 mol

This could react with 0.0375/2= 0.01875 mol of Ca(OH)₂ We have a lot more than that.

Therefore, HCl is the limiting reagent and determines how much CaCl₂ forms.

Based on the balanced reaction, 2 moles of HCl gives 1 mole of CaCl₂

no. of mol of CaCl₂= 0.0375/2= 0.01875 mol

mass in g=n*MM= 0.01875*111= 2.08 g