Question

How many moles of carbon are in 5.2 moles of C7H18?

Answer 1

There is a shortcut to this Chem question. simply look at this problem as if it were a cooking recipe. you have 7 parts Carbon and 18 Parts Hydrogen for a total of 25 parts. Simply divide 5.2 by 25 then multiply by 7 to get your answer.
(5.2/ 25) 7 = 1.456 moles

Answer 2

Answer : The number of moles of carbon are, 36.4 moles.

Explanation : Given,

Moles of $C_7H_{18}$ = 5.2 mole

First we have to determine number of carbon and hydrogen atoms present in $C_7H_{18}$.

As we know that, in $C_7H_{18}$ there are 7 atoms of carbon and 18 atoms of hydrogen.

Now we have to determine the moles of carbon.

As, 1 mole of $C_7H_{18}$ contains 7 moles of carbon.

So, 5.2 moles of $C_7H_{18}$ contains $5.2\times 7=36.4$ moles of carbon.

Hence, the number of moles of carbon are, 36.4 moles.