Answer to Question #138510 in General Chemistry for Alaina

Question

A student titrates a 20.13 mL sample of HCl of unknown concentration. She begins her titration at the 0.00 mL mark and ends the titration at the 33.98 mL mark. The NaOH solution has a molarity of 1.232. What is the concentration of HCl?

Answer 1

HCl + NaOH = NaCl + H2O

N_HCl * V_{solution HCl} = N_NaOH * V_{solution NaOH}

N = C/f_eq, f_eq = 1, N=C.

C_HCl * V_{solution HCl} = C_NaOH * V_{solution NaOH}

C_HCl = (C_NaOH * V_{solution NaOH})/V_{solution HCl}

V_{solution NaOH} = 33,98 mL = 33,98 * 10^-3 L

V_{solution HCl} = 20,13 ml = 20,13 * 10^-3 L

C_HCl = (1,232 * 33,98 *10^-3)/(20,13 * 10^-3) = 2,080.