Assume 100 g of bleach solution:

mass NaOCl = 5.25 g

molar mass NaOCl = 74.44 g/mol

density = 1 g/mL

$\mathbf{moles}\mathbf{}\mathbf{NaOCl}\mathbf{=}\mathbf{5}\mathbf{.}\mathbf{25}\mathbf{}\overline{)\mathbf{g}}\mathbf{\times}\frac{\mathbf{1}\mathbf{}\mathbf{mol}}{\mathbf{74}\mathbf{.}\mathbf{44}\mathbf{}\overline{)\mathbf{g}}}$

**moles NaOCl = 0.07052 mol**

$\mathbf{volume}\mathbf{=}\mathbf{100}\mathbf{}\overline{)\mathbf{g}}\mathbf{\times}\frac{\mathbf{1}\mathbf{}\overline{)\mathbf{mL}}}{\mathbf{1}\mathbf{}\overline{)\mathbf{g}}}\mathbf{\times}\frac{{\mathbf{10}}^{\mathbf{-}\mathbf{3}}\mathbf{}\mathbf{L}}{\mathbf{1}\mathbf{}\overline{)\mathbf{mL}}}$

Calculate the molarity of the bleach solution:

$\mathbf{molarity}\mathbf{=}\frac{\mathbf{0}\mathbf{.}\mathbf{07052}\mathbf{}\mathbf{mol}}{\mathbf{0}\mathbf{.}\mathbf{100}\mathbf{}\mathbf{L}}\phantom{\rule{0ex}{0ex}}\mathbf{molarity}\mathbf{=}\frac{\mathbf{0}\mathbf{.}\mathbf{7052}\mathbf{}\mathbf{mol}}{\mathbf{L}}$

**molarity = 0.7052 M**

**500.0 mL of a pH = 10.26 solution solution:**

Calculate the concentration of NaOCl:

NaOCl → Na^{+} + OCl^{-}

**OCl ^{-} + H_{2}O → HOCl + OH**

A solution of household bleach contains 5.25% sodium hypochlorite, NaOCl, by mass. Assuming that the density of bleach is the same as water, calculate the volume (in mL) of household bleach that should be diluted with water to make 500.0 mL of a pH = 10.26 solution.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Weak Bases concept. If you need more Weak Bases practice, you can also practice Weak Bases practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Cook's class at UB.