Question

In a titration, the endpoint of a neutralization reaction was reached when 37.6 milliliters of an HCl solution was added to 17.3 milliliters of a 0.250 M NaOH solution. What was the molarity of the HCl solution?

1) 0.115 M

2) 0.203 M

3) 0.250 M

4)0.543 M

Answer 1

It is important to know first the titration reaction. For this case, it would be,

NaOH + HCl = NaCl + H2O

We are given volumes and concentration we use the relations of moles and volumes to determine the final answer. We do as follows:

(0.250 mol NaOH / L) (.0173 L) ( 1 mol HCl / 1 mol NaOH ) = 0.00433 mol HCl

Concentration = 0.00433 mol HCl / .0376 L = 0.115 M