Using Molarity to Calculate Volume of Solution
How many liters of a 2.00 M NaCl solution are needed to provide 67.3 g of NaCl?
STEP 1 State the given and needed quantities.
STEP 2 Write a plan to calculate the volume.
grams of NaCl \xrightarrow[]{\text{Molar mass}} moles of NaCl \xrightarrow[]{\text{Molarity}} liters of NaCl solution
STEP 3 Write equalities and conversion factors.
\begin{gathered} 1 \text { mole of NaCl}=58.44\ g \text { of NaCl} \\ \frac{58.44\ g\ NaCl }{1\ mole\ NaCl } \text { and } \frac{1\ mole\ NaCl }{58.44\ g\ NaCl } \end{gathered}
\begin{aligned} & 1\ L \text { of } NaCl \text { solution }=2.00 \text { moles of } NaCl \\ & \frac{2.00 \text { moles NaCl}}{1\ L\ NaCl \text { solution }} \text { and } \frac{1\ L\ NaCl \text { solution }}{2.00 \text { moles } NaCl } \end{aligned}
STEP 4 Set up the problem to calculate the volume.
\underset{\text{Three SFs}}{67.3\ \cancel{g\ NaCl}} \times \underset{\text{Four SFs}}{\overset{\text{Exact}}{\frac{1 \cancel{\text { mole } NaCl} }{58.44\ \cancel{g\ NaCl} }}} \times \overset{\text{Exact}}{\underset{\text{Three SFs}}{\frac{1\ L\ NaCl \text { solution }}{2.00 \cancel{\text { moles } NaCl} }}}=\underset{\text{Three SFs}}{0.576\ L \text { of NaCl solution }}
ANALYZE THE PROBLEM | Given | Need | Connect |
67.3 g of NaCl,2.00 M
NaCl solution |
liters of NaCl
solution |
molar mass of NaCl
molarity |