Question

The percent composition of carbon in C6H12O6 is:

25% C

40% C

7% C

None of the above

Answer 1

To calculate percent composition, you first need to find the molar mass of C (carbon), H (hydrogen) and O (oxygen).
C is 12.01
H is 1.00
O is 16

Then multiply each by the number of atoms of each element in the formula (the number that comes after each element in the equation for example C6 means 6 carbon atoms.

C: 12.01 x 6= 72.06
H: 1x12= 12
O: 16x6= 96

Then add them up.
72.06+ 12+ 96= 180.06

Now find the percent composition of carbon.

72.06/ 180.06 x 100= 40.01%

So the answer is C 40%.