write the structural formula of 2-methylpropane.2,2-dimethylpropane.1,2-dichloroethane.2-chloro-3-methylpentane.2-chloro-2-iodopropane.3,4,4-trimethyl-5-proplynon-2-ene.

We can't draw structures on this forum. Your best bet is to google them.

To write the structural formulas for the given compounds, you need to understand the basic principles of organic chemistry and be able to identify different functional groups and their arrangements in the compounds. Here are the structural formulas for each of the compounds you mentioned:

1. 2-methylpropane:
- Structural formula: CH3-CH(CH3)-CH3

2. 2,2-dimethylpropane:
- Structural formula: (CH3)2C(CH3)2

3. 1,2-dichloroethane:
- Structural formula: Cl-CH2-CH2-Cl

4. 2-chloro-3-methylpentane:
- Structural formula: CH3-CH2-CH(CH3)-CH2-CH2-Cl

5. 2-chloro-2-iodopropane:
- Structural formula: CH3-CH(I)-CH2-Cl

6. 3,4,4-trimethyl-5-proplynon-2-ene:
- Structural formula: CH3-C(CH3)2-C(CH3)3-CH2-CH=CH-CH3

Please note that in structural formulas, the lines represent bonds between atoms, and the atoms or groups of atoms are represented by their respective symbols or abbreviations. The numbers and prefixes indicate the position and number of substituents or functional groups.