Converting Between Moles and Particles

To convert between moles and the number of particles we will use the factor label system from the first unit.

Remember that a mole of anything is defined as 6.022x10²³ of that item. In other words a mole of cats is 6.022x10²³ cats and 6.022x10²³ water molecules is a mole of water.

Let's try a few problems 

How many atoms can be found in 3.91 moles of xenon? 

If you had a bottle that contained 5.69x10²⁴ molecules of water, how many moles of water does the bottle hold? 

Note: when the substance occurs as individual atoms (like a noble gas) we use 6.022x10²³ atoms in the problem. When the substance occurs in molecules (like water) then we use 6.022x10²³ molecules. The math is IDENTICAL, only the units change to match the substance.