A certain sold has a density of 8.0 #"g/cm"^3#. If 16.0 g of this solid are put into 4.00 mL of water, which drawing below most closely represents the volume of water after the solid is added?

1 Answer
Mar 29, 2015

The idea behind placing a solid in a known volume of water is that the volume of water it will displace will be proportional to its mass and density.

https://sites.google.com/site/igcsealifesavingwiki/home/igcse/science/physics/forces-motion/fm2-matter-and-forces

Density is defined as mass per unit of volume. SInce you know the solid's density and its mass, you can easily solve for its volume by

#rho = m/V => V = m/(rho) = (16.0cancel("g"))/(8.0cancel("g")/"cm"^3) = "2.0 cm"^3#

If you take into account the fact that #"1 cm"^3# is equal to #"1 mL"#. the volume of the solid will be

#2.0cancel("cm"^3) * ("1 mL")/(cancel("1 cm"^3)) = "2.0 mL"#

Since the water has a volume of 4.0 mL, adding the solid will raise the water level in the beaker to

#V_("total") = "2.0 mL" + "4.0 mL" = "6.0 mL"#

Therefore, pick a drawing that shows that the total volume in the beaker increased by 50% - from 4.0 mL to 6.0 mL.