Question #137db

1 Answer
Sep 7, 2017

Answer:

#"0.3 g mL"^(-1)#

Explanation:

The thing to remember when looking to determine the density of a given substance is that your ultimate goal is to find the mass of exactly #1# unit of volume of that substance.

That is, in essence, what density means--the mass of #1# unit of volume of a substance.

In your case, the volume of the sample is given to you in milliliters, #"mL"#, so you can say that #1# unit of volume would be #"1 mL"#.

Now, you know that #"24.0 mL"# of this substance have a mass of #"6 g"#, so you can set up this information as a conversion factor to help you find the mass of #"1 mL"# of this substance.

#1 color(red)(cancel(color(black)("mL"))) * "6 g"/(24.0 color(red)(cancel(color(black)("mL")))) = "0.3 g"#

Since this represents the mass of exactly #1# unit of volume of this unknown substance, you can say that the density of the substance will be

#color(darkgreen)(ul(color(black)("density = 0.3 g mL"^(-1)))) -># every #"1 mL"# of this substance has a mass of #"0.3 g"#

The answer must be rounded to one significant figure, the number of sig figs you have for the mass of the sample.