Question

6g of a saturated momo alcohol (A) reacts with sodium to give a gas of volume 1.12 L at S.T.P


Determine the molecular formula of (A).

Answer 1

................2AOH ==> 2AONa + H2

mols H2 = 1.12/22.4 = 0.05 mols
mols AOH = 2x that = 0.1
6g = mols x molar mass and 6/0.1 = 60 g = molar mass.
Take 17 away for the OH group.
Take another 15 away for the first CH3 group
That leaves 60-17-15 = 28
Each CH2 group is 14 so 28/14 = 2 CH2 groups.
Try CH3CH2CH2OH