Question

the % of carbon in the 2nd member of alkane , alkene and alkyne series

Answer 1

Answer: 80% of carbon is present in the second member of the alkane series.

85.75% of carbon is present in the second member of the alkene series.

90% of carbon is present in the second member of the alkyne series.

Explanation:

Ethane is the second member of alkane series

Molecular mass of ethane,$C_2H_6$ = 2(12)+6(1) =30 g/mol

% of carbon in ethane is :$\frac{\text{total mass of carbon atoms present}\times 100}{\text{Molecular mass of the hydrocarbon}}=\frac{24\times 100}{30}=80\%$

80% of carbon is present in the second member of the alkane series.

Propene is the second member of the alkene serires

Molecular mass of propene,$C_3H_6$ = 3(12)+6(1) = 42 g/mol

% of carbon in propene is :$\frac{\text{total mass of carbon atoms present}\times 100}{\text{Molecular mass of the hydrocarbon}}=\frac{36\times 100}{42}=85.75\%$

85.75% of carbon is present in the second member of the alkene series.

Propyne is the second member of the alkyne serires

Molecular mass of propyne,$C_3H_4$ = 3(12)+4(1) = 40 g/mol

% of carbon in propyne is :$\frac{\text{total mass of carbon atoms present}\times 100}{\text{Molecular mass of the hydrocarbon}}=\frac{36\times 100}{40}=90\%$

90% of carbon is present in the second member of the alkyne series.