Answer
The molecular formula is $C_{12}H_{26}$
Work Step by Step
From the name of the compound, we first find out the number of carbons atoms.
Octane = 8C atoms
1,1-dimethylethyl = 4C atoms
Total 12 carbon atoms.
General formula of alkanes is $C_nH_{2n+2} $, where n is the number of carbons atoms.
In this case, n=12. So, the molecular formula is $C_{12}H_{26}$.
