Question #03bbc

1 Answer
Jun 9, 2017

"8.64 g"8.64 g

Explanation:

A substance's density tells you the mass of exactly 11 unit of volume of said substance.

In your case, the density of sodium chloride is said to be equal to "2.16 g cm"^(-3)2.16 g cm3. This tells you that every "1 cm"^31 cm3 of sodium chloride has a mass of "2.16 g"2.16 g.

You can write this as a ratio of mass to volume

"2.16 g"/"1 cm"^3->2.16 g1 cm3 the density of sodium chloride

Now, you know that your sample has a volume of "4.00 cm"^34.00 cm3. Your goal here is to figure out what mass corresponds to "4.00 cm"^34.00 cm3 knowing that "2.16 g"2.16 g correspond to "1 cm"^31 cm3.

To do that, set up the equation as

(color(blue)(?)color(white)(.)"g")/"4.00 cm"^3 = "2.16 g"/"1 cm"^3?.g4.00 cm3=2.16 g1 cm3

Rearrange and solve to find

color(blue)(?) = (4.00 color(red)(cancel(color(black)("cm"^3))))/(1color(red)(cancel(color(black)("cm"^3)))) * "2.16 g" = color(darkgreen)(ul(color(black)("8.64 g")))

The answer is rounded to three sig figs.