Q.10.51 - An Introduction to General, Organic, and Biological Chemistry

Question

What is the molarity of a solution of HCL if 5ml of the HCL solution is titrated with 28.6ml of a 0.145 M NaOH solution?

$\mathrm{HCl}\left(aq\right)+\mathrm{NaOH}\left(aq\right)⟶{\mathrm{H}}_2\mathrm{O}\left(l\right)+\mathrm{NaCl}\left(aq\right)$

Step-by-Step Solution

Answer

The molarity of a solution of HCL is $0.829$M.

Step 1: Given information

Molarity is a proportion of the concentration of a chemical species, in particular of a solute in a solution, as far as the measure of substance per unit volume of solution.

Step 2: Explanation

We have, $5$ml of the HCL solution is titrated with $28.6$ml of a $0.145$M NaOH solution.

$\mathrm{HCl}\left(aq\right)+\mathrm{NaOH}\left(aq\right)⟶{\mathrm{H}}_2\mathrm{O}\left(l\right)+\mathrm{NaCl}\left(aq\right)$

We know,$1\mathrm{LNaOH}=0.145\mathrm{molNaOH}$

Also,$1\mathrm{molNaOH}=1\mathrm{molHCl}$

Calculating the molarity,

$$\begin{gathered} 28.6\mathrm{mLNaOH}\times \frac{1\mathrm{L}}{1000\mathrm{mL}}\times \frac{0.145\mathrm{molNaOH}}{1\mathrm{LNaOH}}\times \frac{1\mathrm{molHCl}}{1\mathrm{molNaOH}} \\ =0.00415\mathrm{mol} \end{gathered}$$

Now,

$\frac{0.00415\mathrm{molHCl}}{\left(\frac{5mL}{1000\mathrm{mL}}\right)}=0.829\mathrm{M}$

Hence the molarity of a solution of HCL is $0.829M$