How many milliliters of 0.130 M HCl are needed to completely neutralize 60.0 mL of 0.100 M Ba(OH)2 solution? Express the volume in milliliters to three significant digits.

Question

must answer with 3 sig figs

Answer 1

First, write the correctly balanced equation.

2HCl + Ba(OH)₂ ==> BaCl₂ + 2H₂O ... balanced equation

Note that it takes TWO moles of HCl for each mole of Ba(OH)₂.

Now, we find the moles of Ba(OH)₂ present:

60.0 ml x 1 L/1000 ml x 0.100 mol/L = 0.00600 moles Ba(OH)₂

Moles of HCl will be 2x this based on the balanced equation. Moles HCl needed = 2 x 0.006 = 0.0120 mol HCl

To find the volume of HCl that will contain the 0.0120 moles of HCl, we simply use the molarity of HCl...

(x L)(0.130 mol/L) = 0.0120 moles

x = 0.0923 L = 92.3 mls (to 3 sig. figs.)