Answer
Structural formula: Picture attached.
Molecular formula: $C_{5}H_{12}$
Empirical formula: $C_{5}H_{12}$
Work Step by Step
In alkane, all the carbon atoms are bonded by hydrogen atoms. In a straight chain alkane with 5 carbon atoms, 12 hydrogen atoms are bonded. Thus, the structutal formula is attached below.
To find the molecular formula, we count the total number of each element in a compound. In pentane, 5 carbon atoms are present and 12 hydrogen atoms are present. Therefore, the molecular formula will be $C_{5}H_{12}$ .
In order to find the empirical formula we take out the simplest ratio of elements in a compound. $5:12$ cannot be simplified further so the empirical formula of pentane is $C_{5}H_{12}$
