 Let's do another group of these law counts in composition. So if we have two samples of water obtained from different sources and they're decomposed into their constituent elements, one sample produces 176.0 grams of oxygen and 22.0 grams of hydrogen and the sample 2 produces 113.6 grams of oxygen and 14.2 grams of hydrogen. Show that the results are consistent with the law of constant composition. So remember for the law of constant composition we want to use the mass ratio and we want it to be a number that's bigger than 1 to make it easy for us to work with. So if we're going to find the mass ratio hopefully we see well oxygen in each sample is bigger than hydrogen, the mass. So when we do the mass ratio for water it's going to be the mass of oxygen over the mass of hydrogen. So hopefully the mass ratio of this sample equals the mass ratio of this sample and that would prove to us the law of constant composition. So the mass ratio of sample 1 we have 176.0 grams by 22. So hopefully when we do the same ratio for sample 2 in that same number what do we get? We get 113.6 grams divided by 14.2 grams and both of these your grams are canceling out. I should have showed you that in the last class. But again let's do it. 113.6 divided by 14.2 and sure enough 80.00. So hopefully you see 8.00, 8.00 those are the same number. So this again is another example that will prove the law of constant composition. Any questions on this one? Hopefully by now we after all these examples we're pretty good at law of constant composition.