Question

a 20.4 g aluminum sphere and a 49.4 g iron sphere are both added to 75.2 mL of water contained in a graduated cylinder. what is the new water level, in millileters in the cylinder?

Answer 1

The level in the beaker will increase because the volumes of the spheres will also be added to the volume of the water. First, we must determine the volume of each sphere. For this, we will use:

density = mass / volume
We can check the density of both aluminum and iron in literature, and given the mass, we may obtain the volume. 

Aluminum:
Density = 2.70 g/ml
Mass = 20.4 g
Volume = 20.4 / 2.7 = 7.56 ml


Iron:
Density = 7.87 g/ml
Mass = 49.4 g
Volume = 49.4 / 7.87 = 6.28 ml

Now, we add these volumes to the volume of water present:
75.2 + 6.28 + 7.56 = 89.04

The new level will be 89.0 ml

Answer 2

The new water level is 145ml