Chapter EH, Problem 53R

Solution

Interpretation: The mass of sodium hypochlorite in 300 mL of bleach needs to be determined.

Concept Introduction: For a mass-to-volume solution, mass% can be calculated as follows:

  $\%m_{\text{A}}=\frac{m_{\text{A}}}{\text{V}}$

Here, $m_{\text{A}}$ is the mass of A and V is the volume of solution in L.

  $0.01575\text{ g}$

According to the question, in household bleach there is 5.25% of solution of sodium hypochlorite is present. The volume of bleach is given 300 mL thus, the mass of sodium hypochlorite can be calculated as follows:

  $\%m=\frac{m}{\text{V}}$

Rearranging the above equation,

  $m=\%m\times V$

Substituting the values,

  $\begin{array}{c}m=5.25\%\left(300\text{ mL}\right)\\ =\left(\frac{5.25}{100}\right)\left(300\text{ mL}\right)\left(\frac{1\text{ L}}{1000\text{ mL}}\right)\\ =0.01575\text{ g}\end{array}$

Thus, the mass of sodium hypochlorite in bleach is $0.01575\text{ g}$ .