Hi, I am doing this question and needed help on how a ratio would be calculated to get the empirical formula. I keep getting an empirical formula of CH2, the mark scheme says C3H7.
I understand that to get C3H7, you have to multiply by 3 but I dont understand why
Here is the question:

Analysis of a different hydrocarbon Y shows that it contains 83.7% by mass of carbon.
Calculate the empirical formula of Y.
Use this empirical formula and the relative molecular mass of Y (Mr = 86.0) to
calculate the molecular formula of Y.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.