Why do the liquids sit on top of each other rather than mixing?
The liquids used will have different weights as they have different masses. The liquids which have a
higher weight have a higher density and will sink below the liquids with lower densities. Density is
the comparison between an objects volume and mass. The equation for density is mass divided by
volume. From this equation, if the mass of the object increases but the volume stays the same, the
density will go up.
= Mass (g)
= Density (g/cm³)
= Volume (cm³)
To measure the densities of the liquids you used, take a weighing scale and weigh 4 measuring
cylinders and record the results. Measure out the same amount of each liquid into the measuring
cylinders and weigh on the scales. Take the first measurement away from the second. The masses of
the liquids should be in the order they are in your experiment with the heaviest mass liquid on the
bottom of the beaker.
Questions
1. If a liquid has a mass of 1kg and a volume of 50cm³. Work out the density.
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2a. Rearrange the density equation to work out the volume. Include units in your equation.
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2b. Work out the volume of a liquid which has a mass of 150g and a density of 5g/cm³.
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3. Using the information above, measure the mass of 10 cm³ of vegetable or sunflower oil, water,
washing up liquid and honey. Record your results in the table below and then work out the densities
for each liquid.
Liquid
Volume
(cm³)
Oil
Water
Washing up liquid
Honey
10
10
10
10
Mass of
measuring
cylinder(g)
Mass of liquid
and measuring
cylinder (g)
Mass of
liquid (g)
Density of
Liquid (g/cm³)