CHEMISTRY 11
Mr. Bellman
Density Equations:
CH 2 Matter and Energy wkst 3
Density = mass
Volume
( 12 )
DENSITY Problems
Volume = mass
density
NAME
Date
____________________
______________ mass = density x volume
1. A 3.50 mL chunk of the element boron has a mass of 8.19 g. Determine the density of boron ( in g / mL ).
Bk _____
SHOW WORK
SIG FIGS
2. Convert the density in question 1 to g / L.
3. A pure iron bar has a mass of 125 g. Determine the volume in mL of the iron bar if the density of iron is 7.86 x 10
3
g / L.
4. Beeswax ( not earwax ) has a density of 961 g / L. If a block of beeswax has a volume of 200.0 mL, determine the mass of the block in grams.
5. Alcohol has a density of 789 g / L. Determine the volume in mL of alcohol needed if you required 46 g of alcohol.
6. The gas neon is contained in a large glass bulb having a volume of 22.4 L. If the density of neon is 9.00 x 10
-4
g / mL, what is the mass in grams of the neon gas in the bulb?
7. A 107.5 g hunk of gold is placed into your pocket and you run to the airport and get onto a plane to S. America. Interpol police catch you and bring you back to school where you are placed under house arrest and a monitoring device does not allow you to go outside OKM for 3 years. Meanwhile back at the lab, you decide to find out the density of gold by placing that hunk of gold into a beaker containing 100.0 mL of water. You find that the volume of water rose to 105.7 mL. What is gold’s density in g / mL?

8. A 70.0 g piece of manganese ( density is 7.20 x 10
3 g / L ) is dropped into a graduated cylinder containing 54.00 mL of water.
Determine the water level in mL after the manganese is inserted.
9. Just for fun, you pour 25.0 mL of each liquid W, X, Y, Z into a 100.0 mL graduated cylinder. The liquids will not dissolve into each other so they stay separated. If 55.0 mL of W had a mass of 107.3 g, 12.0 mL of X had a mass of 51.8 g, 42.5 mL of Y had a mass of
46.8 g, and 115.0 mL of Z had a mass of 74.8 g, determine the densities in g / mL of each liquid and list the layers in order from top to bottom how they will be found in the graduated cylinder.
10. If the density of copper is 8.92 g / mL and the density of magnesium is 1.74 g / cm
3
, what mass of magnesium occupies the same volume as 100.0 g of copper? Hint, you must find volume of copper to start. Remember that 1 mL = 1 cm
3
.
11. Determine the density of the earth in g / mL if the radius of the earth is 6378 km and the mass of the earth is 5.97 x 10
24
kg.
Hint: lots of conversions and volume of sphere equation are needed here.
Answers remember, answers can be expressed in scientific notation or standard notation as long as sig figs are correct.
1. 2.34 g / mL. 2. 2 340 g / L or 2.34 x 10
3
g / L 3. 15.9 mL 4. 192 g
5. 58 mL
9. top
Bottom
Z
Y
W
X
6. 20.2 g
0.650 g / mL
1.10 g / mL
1.95 g / mL
4.32 g / mL
7. 19 g / mL
10. 19.5 g
8. 63.72 mL
11. 5.50 g / mL