Empirical Formula question

4) 0.28g sample of a hydrocarbon was analysed and found to contain 0.24g of carbon.
(Ar C 12, Ar H 1)
a) Calculate the mass of hydrogen in this sample.
b) Calculate the empirical formula of the compound.
c) The compound has a formula mass of 28. State the molecular formula of the compound.
Not sure if I've done this question right, but I got
a) 0.28 - 0.24= 0.04
b) 0.04/0.04=1, 0.24/0.04= 6, therefore it would be C6H
c) I'm pretty sure I'm wrong, but (6 x 12) + (1 x 1) = 73, 73/28= 2.60714285.
I've never been taught this, and the example given isn't that helpful, especially for part c.

I agree with (a).

For part (b), you know the masses of both C and H in grams, so what you do is you calculate the moles of each and then find the simplest whole number ratio of C to H.

So how many moles of carbon (Ar = 12 g/mol) are in 0.24 g and how many moles of hydrogen (Ar = 1 g/mol) are in 0.04 g?

For part (c), calculate the “empirical formula mass” and compare it to the relative formula mass.

If it is the same, then the empirical formula is the molecular formula.

If it is half the relative mass, the molecular formula is double the empirical.

…and so on.

Part b, i missed the moles step. So it would be CH2
c) (1 x 12) + (2 x 1) = 14
28/14= 2
so it would be C2H4... I think?