Another hydrocarbon

Chemistry Level 1

A hydrocarbon contains 92.31% of carbon. If the molecular weight of the hydrocarbon is 78, find its molecular formula.

C X 3 H X 8 \ce{C_3H_{8}} C X 6 H X 6 \ce{C_6H_6} C X 5 H X 20 \ce{C_5H_{20}} C X 4 H X 10 \ce{C_4H_{10}}

Ashish Menon by Ashish Menon , 20, India

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Ashish Menon
Jul 16, 2016

The weight of carbon in the hydrocarbon is 92.31 % 92.31\% of 78 ≈ 72 78 \approx 72 .
72 72 g is the weight of 72 12 = 6 \dfrac{72}{12} = 6 carbon atoms. To complete the molecylar weight we have to add 78 − 72 1 = 6 \dfrac{78 - 72}{1} = 6 hydrogen atoms.
So, the final answer is C X 6 H X 6 \color{#3D99F6}{\boxed{\ce{C_6H_6}}} .

1 Helpful 0 Interesting 0 Brilliant 0 Confused
Rajdeep Das
Jul 16, 2016

molecular weight of benzene is 12(6) + 1(6) =78 others don't have a molecular mass of 78 (Just ignoring first part of question :D)

1 Helpful 0 Interesting 0 Brilliant 0 Confused

Lol, i forgot to take care of the options, but there is another correcr way to obtain the answer.

Ashish Menon - 4 years, 11 months ago

Log in to reply

Yours is obviously much better way, if options not given.

rajdeep das - 4 years, 11 months ago

Log in to reply

Thanks, but your solution is best one if we lack time :)

Ashish Menon - 4 years, 11 months ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...