1. This is my first posting, I am having trouble naming alkanes. I believe my first two problems are correct, but am unsure. The third problem I am having trouble with. I am just not sure what to name the branches coming off the carbon chain. 2. 1. (CH3)2CHCH(CH3)2 2. CH2Ch2CH2CH3 l CH3CH2CH2CHCH2C--H l l CH3CH2 H 3. CH3 H l l CH3CH2CH2CH2--C--C--CH2CH3 l l CH2 CH3 l CH3 3. Problem 1 :4-carbon chain makes it butane. The branches at both C2 and C3 are methyl, so the name is 2,3-dimethylbutane. Problem 2: 6-carbon chain makes it hexane. The branch at C2 is butyl. The branch at C3 is ethyl, so the name is 2-butyl-3-ethylbutane. Problem 3: 8-carbon chain= octane branch at C3 is methyl branches at 4C are methyl and ethyl That is where I get stuck on the name. Is it 4-ethyl-4,3-dimethyloctane?? Thanks very much for your input!