The density of platinum is 21.45 g/cm3 at 20 ∘c. calculate the mass of 80.00 cm3 of platinum at this temperature.

The formula for density = mass/volume.
We know the density (21.45 g/cm³)
We know the volume (80.00 cm³) of the sample
We don't know the mass, so first - solve the equation for mass:

D=m/v  [multiply v to both sides to isolate m]
Dv=m

Now, insert the known value and units...make sure the units cancel properly:
21.45 g/cm³ x 80.00 cm³ = 1716 g

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