Calculating Particle Density in an Ideal Gas at STP

[blazeuofa]

Homework Statement

Determine the number density of particles in a gas at STP (T=273, p=1atm)

Homework Equations

Answer is 2.68x10²⁵

The Attempt at a Solution

pV=nRT


I don't really understand what the "number density of particles" means please help!

 

[Andrew Mason]

Homework Statement

Determine the number density of particles in a gas at STP (T=273, p=1atm)

Homework Equations

Answer is 2.68x10²⁵

The Attempt at a Solution

pV=nRT


I don't really understand what the "number density of particles" means please help!

It means the number of gas molecules per unit volume. Mass density is mass per unit volume. For a gas, the pressure and volume depends on the number of molecules, not their mass.

How many molecules of gas are then in a mole of the gas? How much volume does a mole of gas occupy at STP?

AM

 

[blazeuofa]

hmm I can't quite get the right answer. V=22.4L and avagadros # is the molecules in one mole. How do I piece this together?

 

[NBAJam100]

hmm I can't quite get the right answer. V=22.4L and avagadros # is the molecules in one mole. How do I piece this together?

Be careful of units here... when using PV=nRT what is the units of volume?

So you know Avogadro's # is the number of molecules in one mole... so put the pieces together. As Andrew said, the number density the number of gas molecules per unit volume