the standard entalpy of combustion of ethene gas C2h4 IS -1411.1 KJ/mol at SATP. Calculate Hf for ethene gas.

Question

my work so far:
C2H4 +302--> 2C02 +2H20
H=[(2mol)(-241.8kj/mol)+(2)(-393.5)]-[x]
-1411.1kj/mol=-1270.6-x
x=-1270.6+1411.1

Ans: 52.5 kj which I can't get to

Answer 1

Hf.