Answer:
hydrochloric acid (HCl)
Step-by-step explanation:
balanced equation: Ca(OH)2+2HCl -> CaCl2+2H2O
85.0/36=2.33 mol HCl
120/74=1.62 Ca(OH)2
2.33 mol HCl x 1 mol CaCl2/2 mol HCl = 1.165 mol CaCl2
1.62 mol Ca(OH)2 x 2 mol CaCl2/1 mol Ca(OH)2 = 3.24 mol CaCl2