Question

Calculate the mass in grams for each of the following liquids.

Part A
280 mL of gasoline (d = 0.69 g/mL)
Express your answer to two significant figures and include the appropriate units.


Part B
190 mL of ethanol (d = 0.79 g/mL)
Express your answer to two significant figures and include the appropriate units.

Answer 1

The density is calculated as mass per volume, so if we want to solve for mass, we would multiply density by volume.
For Part A: if we have a density of 0.69 g/mL, and a volume of 280 mL, multiplying these will give a mass of: (0.69 g/mL)(280 mL) = 193.2 g. Rounded to 2 significant figures, this is 190 g gasoline.
For Part B: if we have a density of 0.79 g/mL, and a volume of 190 mL, multiplying these will give a mass of: (0.79 g/mL)(190 mL) = 150.1 g. Rounded to 2 significant figures, this is equal to 150 g ethanol.