I need help understanding this chemistry question?

Question

I don't need help solving it, but just understanding the context of what it's trying to ask:

Calculate the percent composition by mass of the following compounds that are important starting materials for synthethic polymers:

Ex: C3H4O2

So what is this question asking? Is it just finding what percentage an element accounts for in the whole compound?
So I would say something like Carbon accounts for 50% of the compound??

Answer 1

percent composition means % of each element in the compund by mass

if Carbon, the total mass of carbon / molar mass
if Hydrogen, the total mass of hydrogen / molar mass

molar mass of C3H4O2 = 72.06 g/mol
C: 3 x 12.01 = 36.03 is the total mass of carbon

36.03 / 72.06 x 100% = 50.0% C in C3H4O2

If you add % C, H, and O together, it should be 100%

Answer 2

Yes it is just finding what percentage an element accounts for in the whole compound, and yes, carbon accounts for 50% of the compound BY MASS.

The point this problem is trying to illustrate is the difference between a mol% and a mass% (commonly referred to as a weight% or wt%). The mass percent is 50 for Carbon, but the mol% is 33.33% (3 out of 9 atoms are carbon). Hydrogen is 44.44% on a mol% basis and only 5.55 as a mass%. When dealing with a percent composition you really need to know if it is mass or moles!

Answer 3

It is asking what percentage of C3H4O2 is C, H and O. For example the molecular mass of the compound is 56. and the RMM of C is 12 but htere are 3 C hence this adds up to 36.

C is 36/56 X 100 % of C3H4O2, which is 64.29%.

Hope I helped.

Answer 4

Yes you are right.
The questions asking you just to find the percentage composition of mass of each element in the molecule.

This can be solved using the formula
%composition of element=massofthe element/molar mass *100

Regards exorcist

Answer 5

yes, like the mass of the carbon times 3 and mass
of hydrogen times 4 and mass of oxygen times
2. Then u add all the masses and that is the toatal.
Then the mass of the three carbons divided by
the total= percentage.

Answer 6

Does this is going to be basically chemistry? i've got had countless physics in my existence and am tremendously constructive that physics performs a tremendously important function besides. in spite of the certainty that as a believer, i could say that chemistry and physics are the potential with the help of which God keeps the universe.

Answer 7

its asking you to calculate the masses of the individual elements in the compound, and then calculate what percentage of the whole molecule that single element is.