Question

A piece of platinum metal with a density of 21.5 g/cm^3 has a volume of 4.49 cm^3. What is its mass?

Answer 1

`96.5g`

Explanation:

Use the formula for density but rearrange the formula to solve for mass:

`d=m/v` where `d` is the density in `g/(cm^3)`, `m` is the mass in `g`, and `v` is the volume in `cm^3`:

Given the information we can write a formula like so:

`21.5=m/4.49`

We are trying to find the mass so we can rewrite the equation such that we solve for `m`:

`4.49*21.5=m/cancel(4.49)cancel(4.49)`

`4.49*21.5=m`

`96.533=m`

`96.5g=m` (With proper sigfigs)

We could check this answer by substituting our newly found mass and given volume to find density. In doing this, we should get `21.5g/(cm^3)` because that's what the problem told us;

Check:
`d=96.5/4.49`

`d=21.5`