# How to count molecules and determine density, partial pressure and total pressure?

1. Jul 23, 2010

### chemistry4all

How to count molecules and determine density, partial pressure and total pressure???

1. The problem statement, all variables and given/known data

Consider three identical boxes each containing a different mixture of O2 and N2. In box #1 are 3 molecules of O2 and 7 molecules of N2. In box #2 are 1 molecule of O2 and 2 molecules of N2. In box #3 are 10 molecules of O2 and 3 molecules of N2. If temperature and volume for all three samples are the same, rank them (use "less than," "greater than," or equal symbols; 1< 2 < 3 or 2 > 1 = 3 with respect to:

a) total pressure

b)partial pressure of nitrogen

c)density

2. Relevant equations

My attempt is according to counting the number of molecules is

a) total pressure is 2 < 1 < 3

b) partial pressure is 2 < 3 < 1

c)density is 2 < 1 < 3

I want to just make sure and compare with someone if I am correct and if not please explain how to determine this thank you.

3. The attempt at a solution