A compound of molar mass 177 g>mol contains only carbon, hydrogen, bromine, and oxygen. Analysis reveals that the compound contains eight times as much carbon as hydrogen by mass. Find the molecular formula.

Video transcript

Hi everyone here, we have a question telling us that analysis of the compound shows that the compound contains 12 times as much carbon as hydrogen by mass. If the compound only contains carbon, hydrogen bruning and oxygen determine its molecular formula and it tells us that the molar mass equals 161 g per mole. So we are going to say that our formula is C X H Y b R. Oh, So we know that our total molar mass is 161. So that's going to equal the molar mass of carbon, which is 12.01 times x times how many carbon we have? Plus 1.1. The molar mass of hydrogen, which is found on the periodic table. Why? Plus the mass of grooming, Which is 79 0. plus The molar mass of oxygen, which is 16.00. So equals 12 point 12. Why? Plus 1.01? Y plus plus 79.90. And we got that because 12. X equals 12 times 1.1 Y. And we know that because we have 12 times the mass of hydrogen. So we have 12 times the mass of hydrogen equals 12.1. The molar mass of carbon times X. So 12 .01 x equals 12.12 y. So now we have Equals 13.13 Y Plus 95.9. And we're going to subtract 95.9 from both sides, so 161 equals 95. Equals 13.13 Y. And then we're going to divide both sides by 13.13. So y equals 4.95 And we're going to Ram that off to five. Now, we need a software X. So 12.01 x equals 12.12 Y. And we're going to substitute N. Y. So X equals 12.12, divided by 12. times five. So x equals five. That means that our empirical formula is c. five H. Five B R O. And that is our final answer. Thank you for watching. Bye.