Answer
$$21.4 \space mL$$
Work Step by Step
1. Use the density as a conversion factor to calculate the volume of silver:
$$V_{Ag} = 35.6 \space g \times \frac{1 \space mL}{10.5 \space g} = 3.39 \space mL$$
or use the equation:
$$density = \frac{mass}{volume} \longrightarrow 10.5 \space g/mL = \frac{35.6 \space g}{volume}$$ $$volume = \frac{35.6 \space g}{10.5 \space g/mL} = 3.39 \space mL$$
2. Find the total volume:
$$V_{total} = V_{Ag} + V_{H_2O} = 3.39 \space mL + 18.0 \space mL = 21.4 \space mL$$
