Question

The concentration of 20 mL of HCl is determined by titrating with NaOH. The titration reaches its endpoint after adding 10.1 mL of 0.859 M NaOH. What was the original concentration of the HCl

Answer 1

Explanation:

The reaction equation for this reaction is as follows.

        $NaOH + HCl \rightarrow NaCl + H_{2}O$

The given data is as follows.

        $M_{1}$ = ?,    $V_{1}$ = 20 ml

        $M_{2}$ = 0.859 M,    $V_{2}$ = 10.1 ml

Hence, we will calculate the original concentration of HCl as follows.

          $M_{1}V_{1} = M_{2}V_{2}$

         $M_{1} \times 20 ml = 0.859 M \times 10.1 ml$

        $M_{1}$ = 0.434 M

Thus, we can conclude that the original concentration of the HCl is 0.434 M.