Question

A 0.00100 moles sample of ca(oh)2 requires 25.00 ml of aqueous hcl for neutralization. how many moles of acid are contained in the 25.00 ml?

a.0.0200
d.4.00 ´ 10–5
b.0.0400
e.none of the above
c.0.002

Answer 1

The balanced chemical equation for the reaction is as follows;
Ca(OH)2 + 2HCl —> CaCl2 + 2H2O
The stoichiometry of Ca(OH)2 to HCl is 1:2.
Number of Ca(OH)2 moles reacted = 0.00100 mol
Therefore number of HCl moles that should react with base is double the amount of moles of base reacted.
Number of acid moles in 25.00 ml
= 0.00100 mol x2 = 0.00200 mol
Correct answer is 0.002 mol