Determine the molecular formula of an alkane if its relative molecular weight is 100

Determine the molecular formula of an alkane if its relative molecular weight is 100: make up 2 homologues and isomers, give them a name

In accordance with the condition of the problem, we will write the data:
CxNu – hydrocarbon (alkane);

Mr (CxHy) = 100;

Determine the formula: CxNy -?

Calculations based on the general formula for alkanes:
CnH2n + 2 = 100;

12n + 2n = 100 – 2;

14n = 98

n = 7

C7H16 heptane; M (C7H16) = 100 g / mol.

Homologues of heptane:
C6H14 – hexane; С8Н18 – octane.

Isomers:
H3C – CH2 – CH – (CH3) – CH2 – CH2 – CH3 – 2 – methyl hexane;

H3C – CH – (CH3) – CH2 – CH2 – CH2 – CH3 – 3 – methyl hexane.

Answer: С7Н16 – heptane (alkane).