Structure of 2,2-dimethyl-4-propyloctane is in the Word document below.
Answer is: six secondary carbons.
Secondary carbon (2°) is attached to two other carbons. Secundary carbons are third, fifth, sixth and seventh in octane and first and second in propyl.
Primary carbon (1°) is attached to only one carbon.
Tertiary carbon (3°) is attached to three other carbons.
Quaternary carbon (4°) is attached to four other carbons.
