00:03
In this question, we have calcium and oxygen reacting, and we're asked how many grams of calcium are consumed when 156 .8 milliliters of o2 gas measured spp react with calcium.
00:19
So, stp is standard temperature and pressure, and that means 273 kelvin and one atmosphere.
00:25
So first, i want to make sure all my units are correct.
00:28
We're going to standardize the unit so we can use them, use each of these values in the ideal.
00:33
Gas equation.
00:35
So my volume needs to be in liters.
00:38
So to get from mill liters, so liters, i'll just divide by a thousand and that gives me 0 .1568 liters.
00:45
My temperature needs to be in calvin, which it already is, and my pressure needs to be in atmosphere.
00:49
So we're good on units now.
00:52
So now what i'm going to do is use the ideal gas equation to figure out how many moles of oxygen are in this 156 .8 milliliters of the gas.
01:05
So the ideal gas equation is p v equals n r t, where p is pressure, which we have here, v is volume, which we have here, n is what we're looking for.
01:17
That's the number of moles.
01:20
R is a constant, and t is temperature, which we have right here.
01:25
So we're just going to fill in all of those values...