Question

substance #2
mass: 7.39 g
volume of water: 30.5 ml
volume of water and object: 40.3 ml
b. substance #2

Explanation:

Step1: Find volume of substance #2

The volume of the substance can be found by the difference in the volume of water and object and the volume of water alone.
$V = 40.3\ ml - 30.5\ ml$
$V=9.8\ ml$

Step2: Calculate density of substance #2

Density ($
ho$) is given by the formula $
ho=\frac{m}{V}$, where $m$ is mass and $V$ is volume. Given $m = 7.39\ g$ and $V = 9.8\ ml$.
$
ho=\frac{7.39\ g}{9.8\ ml}\approx0.754\ g/ml$

Answer:

The density of substance #2 is approximately $0.754\ g/ml$