Petroleum ether obtained on fractionation of petroleum contains pentane, hexane and heptane. State whether the statement is true or not.

Answer

To determine whether the statement "Petroleum ether obtained on fractionation of petroleum contains pentane, hexane, and heptane" is true or false, we can follow these steps:

### Step 1: Understand Fractionation of Petroleum
Fractionation is a process used to separate a mixture into different parts (fractions) based on their boiling points. Petroleum, which is a complex mixture of hydrocarbons, is subjected to this process to obtain various useful products.

**Hint:** Fractionation separates components based on their boiling points.

### Step 2: Identify the Components of Petroleum
Petroleum consists of a variety of hydrocarbons, including aliphatic (straight-chain or branched) and aromatic (ring-shaped) hydrocarbons.

**Hint:** Consider the types of hydrocarbons present in petroleum.

### Step 3: Define Petroleum Ether
Petroleum ether is a term used to describe a fraction of petroleum that primarily contains aliphatic hydrocarbons. It does not actually contain any ether compounds; the term can be misleading.

**Hint:** Remember that "ether" in petroleum ether does not imply the presence of ether compounds.

### Step 4: List the Major Hydrocarbons in Petroleum Ether
The major hydrocarbons found in petroleum ether include:
- Pentane (C5H12)
- Hexane (C6H14)
- Heptane (C7H16)

These hydrocarbons are present in significant amounts in the aliphatic fraction of petroleum.

**Hint:** Focus on the specific hydrocarbons mentioned in the statement.

### Step 5: Evaluate the Statement
Since pentane, hexane, and heptane are indeed major components of petroleum ether, we can conclude that the statement is true.

**Hint:** Compare the components listed in the statement with the known composition of petroleum ether.

### Conclusion
The statement "Petroleum ether obtained on fractionation of petroleum contains pentane, hexane, and heptane" is **true**.

---