As we said, the ideal gas law uses R, which is our gas constant. But realize that the gas constant R can have two different values depending on the situation. Now, the two terms you'll tend to see when it comes to the R constant is the first one we talked about earlier, R being equal to 0.08206. We utilize this value when dealing with the ideal gas law, but R can also equal 8.314.

This happens when we're dealing with speed, velocity or energy. If a question is dealing with the speed of an object or a subatomic particle, or dealing with the energy of a reaction or solution, the R converts to 8.314. Now the conversion factor between the R groups is that one liter times atmospheres equals 101.325 joules. So we have our 0.08206. Here we use the conversion factor.

So remember we want to get rid of liters times atmospheres, so we put them on the bottom. So one liters times atmosphere on the bottom is 101.325 Joules. Here on top, liters times atmospheres cancel out and that's how we end up with joules at the end. When you plug this in you get a long string of numbers as 8.3147295 joules over moles times K, but we just focus on the 8.314 portion.

I know there's a seven there when you work it out completely, but to keep it simple, books were just listed as 8.314. So just keep in mind the gas constant can be two different numbers. And remember, with the ideal gas law we use this value and when dealing with speed, velocity or energy we use this value of 8.314.