Establish the formula for the limiting tertiary amine, the hydrogen vapor density of which is 36.5.

Given:
The general formula of the limiting tertiary amine is CnH2n + 3N
D H2 (CnH2n + 3N) = 36.5

Find:
CnH2n + 3N -?

Solution:
1) M (CnH2n + 3N) = D H2 (CnH2n + 3N) * M (H2) = 36.5 * 2 = 73 g / mol;
2) M (CnH2n + 3N) = Mr (CnH2n + 3N) = Ar (C) * N (C) + Ar (H) * N (H) + Ar (N) * N (N) = 12 * n + 1 * (2n + 3) + 14 * 1 = 14n + 17;
3) 73 = 14n + 17;
14n = 56;
n = 4;
4) The formula of the limiting primary amine is C4H11N – C2H5-N- (CH3) 2 – dimethylethylamine.

Answer: The formula of the limiting primary amine is C4H11N – C2H5-N- (CH3) 2 – dimethylethylamine.