DensityNotes

Remember: Changes in temperature and pressure have little effect in the densities of liquids and solids.

Also: generally an increase in temperature will increase the volume of the sample while the mass remains constant, thus the density will decrease

Density= mass

volume

Density's units are grams/liters or grams/centimeters cubed

Formula for determining Density:

1. determine which part is missing and which part you know (i.e. either the mass, volume, or density is what you are trying to determine)
2. write out the formula that you need to use (Density= mass/volume)
3. plug the numbers you are given into the formula and write a constant for the part you are trying to determine
4. multipy or divide to determine the answer
5. check to make sure you have the right answer in the right units with the correct number of significant figures!

Example

Question: A piece of lead has a mass of 22.7 grams and occupies a volume of 2.00 liters. What is the density of the lead?

Solution:

• Determine what you have and what is missing

mass=22.7 grams, volume=2.00 liters,

density is what is missing

• Write out the formula

Density=mass

volume

• Plug in the numbers

X=22.7 grams

2.oo liters

• Now solve for X:

Now Try it on Your Own

Question: A piece of silver has a mass of 7.o grams and occupies a volume of 2.9 liters. What is the density of the silver?

Answer: The density of the silver is 2.4 grams/liters