How do you calculate the density of a 6.75 g solid with a volume of 5.35 cm3?

Question

Wyatt Adkins · Accepted Answer

#"1.26 g cm"^(-3)#

Trying to find the mass of one unit of volume of a substance given its mass and the volume it occupies is your goal when attempting to calculate the density of that substance.

As you know, the density of a substance is defined as the mass of exactly one unit of volume of that substance. In your case, the volume of the sample is expressed in cubic centimeters, #"cm"^3#, which means that one unit of volume will be #"1 cm"^3#.

So, you must find the mass of #"1 cm"^3# of this unknown solid. To do that, use the fact that the mass of the solid is uniformly distributed in the volume it occupies.

Thus, you will have

#1 color(red)(cancel(color(black)("cm"^3))) * "6.75 g"/(5.35color(red)(cancel(color(black)("cm"^3)))) = "1.26 g"#

You can now say that because #"1 cm"^3# of this solid has a mass of #"1.26 g"#, the density of the solid, #rho_"solid"#, is

#color(green)(|bar(ul(color(white)(a/a)color(black)(rho_"solid" = "1.26 g cm"^(-3))color(white)(a/a)|)))#

Three sig figs are used to round the result.

Olivia Anton · Answer

undefined To calculate density, divide an object's mass by its volume. In this example, the density of the solid is equal to mass / volume, which equals 6.75 g / 5.35 cm³, or density ≈ 1.26 g/cm³.