Question

Question #d64a6

Answer 1

`"1.2 g mL"^(-1)`

Explanation:

The idea here is that you can determine the volume of the object by looking at the difference between the water levels.

When you add the object to the water, a volume of water that is equal to the volume of the object will be displaced `->` the water level will rise in the cylinder.

In your case, the volume of the water displaced by the object will be equal to

`"29.4 mL " - " 25.1 mL = 4.3 mL"`

This means that the volume of the object is equal to `"4.3 mL"`.

Now, in order to find its density, you must figure out the mass of exactly `1` unit of volume, i.e. of `"1m L"`, occupied by the object.

Since you know that `"4.3 mL"` have a mass of `"5.1 g"`, you can say that `"1 mL"` will have a mass of

`1 color(red)(cancel(color(black)("mL"))) * "5.1 g"/(4.3 color(red)(cancel(color(black)("mL")))) = "1.186 g"`

This means that the density of the object, i.e. its mass per unit of volume, will be equal to

`color(darkgreen)(ul(color(black)("density = 1.2 g mL"^(-1))))`

The answer is rounded to two sig figs.