Question 3 of 28intermediate🔧 ApplyShort Answer2 marks

How many structural isomers can you draw for pentane?

Correct Answer

We can draw three structural isomers for pentane. Structural isomers are compounds with identical molecular formula but different structures.

Pentane has the molecular formula C5H12C_5H_{12}. One isomer is the straight-chain pentane listed in the table. Similar to butane, which has straight and branched carbon 'skeletons', pentane can also be arranged in different ways. These include the straight chain and two distinct branched-chain arrangements, resulting in a total of three isomers.

Exercise: QUESTIONS | Q: 1 | (Page 11)
For More Understanding

Explanation

The provided context defines structural isomers as compounds with the same molecular formula but different structures, using butane (C4H10C_4H_{10}) as an example to show how different carbon 'skeletons' (straight and branched) create isomers. Although the text does not explicitly draw the isomers for pentane (C5H12C_5H_{12}), it provides the formula and the concept of branching. Applying this concept to the five carbon atoms of pentane allows us to determine there are three possible structures: one straight chain and two branched chains.

Solution Steps

  1. Step 1: Identify the molecular formula of pentane from the text, which is C5H12C_5H_{12}.

  2. Step 2: Recall the definition of structural isomers: compounds with identical molecular formulas but different structures.

  3. Step 3: Apply the concept of carbon skeletons (straight and branched) shown for butane to pentane. The five carbon atoms can be arranged in a straight chain, or in two different branched formations, totaling three isomers.

PreviousNext