Question

What is the percent composition of each element in vitamin E, `C_29H_50O_2`?

Answer 1

The composition of Vitamin E is `"80.87 % C, 11.70 % H"`, and `"7.43 % O"`.

Explanation:

We can calculate the molecular mass of Vitamin C as follows:

`29 color(red)(cancel(color(black)("atoms C"))) × "12.01 u"/(1 color(red)(cancel(color(black)("atom C")))) = "348.29 u"`
`50 color(red)(cancel(color(black)("atoms H"))) × "1.008 u"/(1 color(red)(cancel(color(black)("atom H")))) = "50.40 u"`
`2 color(red)(cancel(color(black)("atoms O"))) × "16.00 u"/(1 color(red)(cancel(color(black)("atom O")))) =color(white)(l) "32.00 u"`
`"TOTAL"color(white)(mmmmmmmm) = "430.69 u"`

The mass percentages of each element are:

`"% C" = (348.29 color(red)(cancel(color(black)("u"))))/(430.69 color(red)(cancel(color(black)("u")))) × 100 % = 80.87 %`
`"% H" = (50.40 color(red)(cancel(color(black)("u"))))/(430.69 color(red)(cancel(color(black)("u")))) × 100 % = 11.70 %`
`"% O" = (32.00 color(red)(cancel(color(black)("u"))))/(430.69 color(red)(cancel(color(black)("u")))) × 100 % =color(white)(ll) 7.43 %`