Please help me with these Chemistry questions.

Question

How are organic compounds classified?

a. by the presence or lack of benzene rings

b. by the number of branches they contain

c. by the number of hydrogens bonded to the parent chain

d. by their functional groups

You have a straight-chain, saturated hydrocarbon. There are seven carbons. How many hydrogens are there in this molecule? 

The image above is made from a compound that has a very long chain of repeating molecules and a high molar mass. This type of compound and those similar to it are known as...

What is the name of the parent chain in the picture below?

Answer 1

1). by their functional group

2). There would be 2n + 2 hydrogens or 2x7 + 2 = 16 hydrogens

3). These compounds are known as polymers

4). The parent chain has 7 carbons, so it has the name hexane