A 28.8 mL sample of HCl is titrated with NaOH. If 39.5 mL of 0.639 M NaOH is needed to reach the endpoint, what is the concentration (M) of the HCl solution

0.8764 M

Explanation:

Equation of the reaction:

NaOH + HCl --> NaCl + H2O

Number of moles = molar concentration × volume

= 0.039 × 0.639

= 0.0252 mol

By stoichiometry, 1 mole of HCl reacted with 1 mole of NaOH. Therefore, number of moles of HCl = 0.0252 mol

Molar concentration of HCl = number of moles ÷ volume

= 0.0252 ÷ 0.0288

= 0.8764 M of HCl.

chemistry sucks a**

explanation: