00:02
Hi, in this problem, we are given the chemical composition in terms of percentage of a diabasic acid which contains carbon as 26 .7%, hydrogen equals to 2 .2 % and oxygen equals to 71 .1%.
00:17
Also, the vapor density of the compound is 45.
00:21
We need to find out the molecular formula of this compound out of the given options, a, b, c and g.
00:27
First of all, we'll find out the molecular mass of the compound molecular mass is equal to two multiply vapor density that is 45 and this comes out to be 90 gram now we will find out the mole ratio of different elements so elements given to us are carbon hydrogen and oxygen let us write their percentage by masses or this can be considered as their mass in grams out of 100 so you can write 26 .7 for carbon 2 .2 gram for hydrogen, 71 .1 gram for oxygen.
01:09
Atopic masses are 12 gram per mole for carbon, 1 gram mole per for hydrogen, and for oxygen it is 16 gram per mole.
01:17
Now, we will find out the moles by dividing the mass given with the molar mass, that is 26 .7 divided by 12.
01:31
This gives the value as 2 .2 then 2 .2 divided by 1 equals to 2 .2 and 71 .1 divided by 16 is equals to 4 .4.
01:47
Now let's find out the molar ratio by reminding the number of moles of all these substances with the least number of moles.
01:54
So we can write 2 .2 divided by 2 .2 equals to 1 mole...