Write the IUPAC name for straight-chain hydrocarbon with this formula: CH3CH2CH2CH2CH2CH2CH3

Write the IUPAC name for any branched-chain hydrocarbon with this formula:C9h20

a. seven carbon chain. Heptane.

b.

CH3CH((CH2)5-CH3)CH3

Longest chain: 8
Numbering from the left..
2-methyl-octane

To write the IUPAC name for a straight-chain hydrocarbon, follow these steps:

1. Count the number of carbon atoms in the molecule. In this case, the molecule has 8 carbon atoms.
2. Use the prefix "hept" to indicate the number of carbon atoms (C7) in the hydrocarbon.
3. Add the suffix "-ane" to indicate that the hydrocarbon is an alkane.
4. Combine the prefix and suffix to form the IUPAC name: heptane.

Therefore, the IUPAC name for CH3CH2CH2CH2CH2CH2CH3 is heptane.

Now, let's move on to the branched-chain hydrocarbon with the formula C9H20. To find the IUPAC name for a branched-chain hydrocarbon, we need to determine the arrangement of carbon atoms.

1. Draw the structure of the branched hydrocarbon, making sure to include all carbon and hydrogen atoms.
CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3

2. Count the number of carbon atoms in the main chain. In this case, the main chain has 6 carbon atoms.

3. Identify any branches or side chains. Here, we have a single branch at the third carbon atom.

4. Determine the length of the branch. The branch has 3 carbon atoms.

5. Use the prefix "non" to indicate the number of carbon atoms (C9) in the hydrocarbon.

6. Indicate the position of the branch using a number. The branch is attached to the third carbon atom.

7. Add the suffix "-ane" to indicate that the hydrocarbon is an alkane.

8. Combine the prefix, branch information, and suffix to form the IUPAC name: 3-methylnonane.

Therefore, the IUPAC name for any branched-chain hydrocarbon with the formula C9H20 is 3-methylnonane.