Alright, I've cracked it with the help of one of my classmates.
Firstly, write down the equation:
X + O2 --> CO2 + H2O
then find out the moles of X, CO2 and H2O by the masses given and their respective Mr:
n(x) = 0.43/58 = 0.00741379 mol
n(CO2) = 1.1/44 = 0.025 mol
n(H2O) = 0.45/18 = 0.025 mol
put these molar quantities into the simplest whole number ratio by dividing each individually by the smallest value:
which gives a ratio of 1 : 3 : 3
now assign these values to the relevant molecule and make a balanced equation:
(1)X +4O2 --> 3CO2 + 3H2O
use this information to create a molecule with an Mr of 58:
from the equation, you know it has 3 carbons and 6 hydrogen atoms, but that only adds up to 42. however, you know it has at least 1 oxygen molecule, therefore giving you an Mr of 58. this Molecule has the general formula C3H6O which is both it's molecular AND its empirical formula.
Hope It helps!