Question

A 16%(m/m) solution contains 10 grams of NaOH. It also contains ___ grams of water.

Answer 1

1) List the known and unknown quantities.

Concentration: 16%(m/m).

Mass of solute: 10 g NaOH.

Mass of solvent: unknown.

2) Set the equation.

Mass percent.

$Mass\text{ }\%=\frac{grams\text{ }of\text{ }solute}{grams\text{ }of\text{ }solvent}*100$

3) Plug in the known values and solve for grams of solvent (water).

$16\%=\frac{10\text{ }g\text{ }NaOH}{grams\text{ }of\text{ }solvent}*100$

.

$grams\text{ }of\text{ }solvent=\frac{10\text{ }g\text{ }NaOH}{16}\times100$$grams\text{ }of\text{ }solvent=62.5\text{ }g\text{ }H_2O$

The 16%(m/m) solution contains 62.5 g H2O.

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