Question

In a laboratory activity, a student titrates a 20.0 milliliter sample of Hcl(aq) using 0.025 M NAOH (aq). In one of the titration trails, 17.6 milliliters of the base solution exactly neutralizes the acid sample. Calculate the concentration f the hydrochloric acid using the titration data

Answer 1

Answer:

$\large \boxed{\text{0.022 mol/L}}$

Explanation:

1. Balanced chemical equation.

$\rm HCl + NaOH \longrightarrow \, NaCl + H_{2}O$

2. Moles of NaOH

$\text{Moles of NaOH} =\text{ 17.6 mL NaOH} \times \dfrac{\text{0.025 mmol NaOH }}{\text{1 mL NaOH }} = \text{0.440 mmol NaOH }$

3. Moles of HBr

The molar ratio is 1 mmol HCl:1 mmol NaOH

$\text{Moles of HCl}= \text{0.440 mmol NaOH} \times \dfrac{\text{1 mmol HCl}}{\text{1 mmol NaOH}} =\text{0.440 mmol HCl}$

4. [HCl]

$\text{[HCl]} = \dfrac{\text{0.440 mmol HCl}}{\text{20.0 mL HCl}} = \textbf{0.022 mol/L}\\\text{The concentration of HCl is \large \boxed{\textbf{0.022 mol/L}} }$}