Answer
16 mL of that solution contains 4.0 g of $NaF$.
Work Step by Step
1. Identify the conversion factors:
- Since the $NaF$ solution is 25% (m/v):
25 g (Solute) = 100 mL (Solution)
So: $\frac{25 \space g \space (Solute)}{100 \space mL \space (Solution)}$ and $\frac{100 \space mL \space (Solution)}{25 \space g \space (Solute)}$
2. Calculate the volume of that solution that contains 4.0 g of $NaF$:
$4.0 \space g \space (Solute) \times\frac{100 \space mL \space (Solution)}{25 \space g \space (Solute)} = 16. \space mL \space (Solution)$
