4:19 know the general formula for alkanes

Alkanes have the general formula C_nH_2n+2

This means that to work out the number of hydrogens, you double the number of carbons and then add two.

Spec	Q'stion	Ans	MS
4:19	Jan '14 (1), Q 6 a	Answer	MkS
4:19	Jan '14 (1), Q 6 c	Answer	MkS
4:19	Jan '15 (1), Q 7 b i	Answer	MkS
4:19	Jan '18 (1), Q 14 b	Answer	MkS
4:19	May '11 (1), Q 8 b i	Answer	MkS
4:19	May '11 (1), Q 8 b ii	Answer	MkS
4:19	May '12 (1), Q 7 a ii	Answer	MkS
4:19	May '13 (2R), Q 5 b i	Answer	MkS
4:19	May '13 (2R), Q 5 b iii	Answer	MkS
4:19	May '13 (2R), Q 5 b v	Answer	MkS
4:19	May '14 (1), Q 9 c i	Answer	MkS
4:19	May '17 (1R), Q 11 a i	Answer	MkS
4:19	May '17 (1R), Q 11 a ii	Answer	MkS