Final answer:
The density of the vase can be found using the formula ρ = m ÷ V, which with the given mass of 157 grams and volume of 18.65 mL, results in a density of 8.42 g/mL.
Step-by-step explanation:
The student is asking how to find the density of a vase that seems to be made of solid platinum, given its mass and the volume of water it displaces. The formula for density (ρ) is mass (m) divided by volume (V), so to find the density of the vase, you would use the given mass of 157 grams and the volume of displaced water which is 18.65 mL (which is equal to the volume of the vase).
Therefore, the density of the vase is 157 g ÷ 18.65 mL = 8.42 g/mL.
Comparing this density to reference values for various materials can help to confirm if the vase is indeed made of platinum, as platinum has a density of approximately 21.45 g/cm³ (or 21.45 g/mL).