Question

The volumes of a sample of lead and a sample of platinum are the same: 2 cm3. The density of lead is 11.3 g/cm3 and the density of platinum is 21.5 g/cm3.
Which is an accurate description of their relative masses?
A. The masses of the lead and platinum samples are the same.
B. The mass of the lead sample is greater than the mass of the platinum sample.
C. The mass of the platinum sample is greater than the mass of the lead sample.

Answer 1

The answer is C. The mass of the platinum sample is greater than the mass of the lead sample. As I explained in a previous answer, if they are the same volume, but one is heavier, then it must be more dense. In this particular example, the platinum is more dense than the lead, and therefore has more mass.

Answer 2

Answer:

The mass of the platinum sample is greater than the mass of the lead sample (option C.)

Explanation:

Density is a magnitude that allows you to measure the amount of mass in a given volume of a substance. Then, the expression for the calculation of density is the ratio between the mass of a body and the volume it occupies:

$d=\frac{m}{V}$

From this expression it can be deduced that the density is inversely proportional to the volume: the smaller the volume occupied by a given mass, the greater the density.

The density of lead is 11.3 $\frac{g}{cm^{3} }$ . Then it is possible to apply a rule of three as follows: if in 1 cm³ of lead there is 11.3 g of substance, in 2 cm³ how much mass is there?

$mass=\frac{2cm^{3}*11.3 g }{1cm^{3} }$

mass=22.6 g

The density of platinum is 21.5 $\frac{g}{cm^{3} }$. Then it is possible to apply a rule of three as follows: if in 1 cm³ of platinum there is 21.5 g of substance, in 2 cm³ how much mass is there?

$mass=\frac{2cm^{3}*21.5 g }{1cm^{3} }$

mass=43 g

Then, you can see that the mass of the platinum sample is greater than the mass of the lead sample (option C.)