Question

Match the following: \(\begin{array}{ll}\text { List 1 } & \text { List 2 }\end{array}\) (Petroleum fractions) \(\quad\) (Approximate composition) 1\. Gasoline (1) \(\mathrm{C}_{10}\) to \(\mathrm{C}_{15}\) 2\. Kerosene (2) \(\mathrm{C}_{6}\) to \(\mathrm{C}_{8}\) 3\. Lubricating oil (3) \(\mathrm{C}_{30}\) to \(\mathrm{C}_{40}\) 4\. Pitch and asphalt (4) \(\mathrm{C}_{17}\) to \(\mathrm{C}_{20}\) The correct matching is: \(1 \quad 2 \quad 3\) 4 (a) \((2)\) (1) (3) (4) (b) (1) (3) (4) (2) (c) (1) (2) (4) (3) (d) (2) (1) (4) (3)

Short answer

Option (d) is correct: Gasoline (2), Kerosene (1), Lubricating oil (4), Pitch and asphalt (3).

Step-by-step solution

Understand the problem

We need to match each item in List 1 (petroleum fractions) with the corresponding composition in List 2 (approximate composition) and choose the correct option from the given choices.

Analyze the items in List 1

List 1 contains different petroleum fractions: 1. Gasoline, 2. Kerosene, 3. Lubricating oil, 4. Pitch and asphalt. Each of these fractions has a typical carbon chain length associated with it.

Match the items with List 2 compositions

Identify which carbon ranges in List 2 correspond typically to each fraction in List 1: - Gasoline is typically associated with lighter molecules, usually in the range of \( \mathrm{C}_{6} \) to \( \mathrm{C}_{8} \).- Kerosene is usually comprised of slightly heavier molecules in the range of \( \mathrm{C}_{10} \) to \( \mathrm{C}_{15} \).- Lubricating oil has a broader range in \( \mathrm{C}_{17} \) to \( \mathrm{C}_{20} \).- Pitch and asphalt are composed of very heavy molecules, typically in the range of \( \mathrm{C}_{30} \) to \( \mathrm{C}_{40} \).

Create the correct matches

Now match the items from List 1 to List 2 based on the above analysis. - 1. Gasoline matches with 2 (\( \mathrm{C}_{6} \) to \( \mathrm{C}_{8} \)).- 2. Kerosene matches with 1 (\( \mathrm{C}_{10} \) to \( \mathrm{C}_{15} \)).- 3. Lubricating oil matches with 4 (\( \mathrm{C}_{17} \) to \( \mathrm{C}_{20} \)).- 4. Pitch and asphalt matches with 3 (\( \mathrm{C}_{30} \) to \( \mathrm{C}_{40} \)).

Choose the correct option from given choices

The correct matches are: 1 with (2), 2 with (1), 3 with (4), 4 with (3). Looking at the options: - Option (d) lists 1 as (2), 2 as (1), 3 as (4), and 4 as (3), which matches our findings.

Key concepts

Gasoline Composition

Gasoline is a petroleum fraction known for its use primarily as a fuel in internal combustion engines, like those in cars. Its composition predominantly consists of hydrocarbons in the carbon range of \( \mathrm{C}_{6} \) to \( \mathrm{C}_{8} \), which are relatively light molecules. These hydrocarbons include alkanes, cycloalkanes, and aromatic hydrocarbons.
These lighter molecules are what give gasoline its fluidity and volatility, characteristics that are crucial for efficient combustion. The volatility is essential as it allows gasoline to vaporize easily for ignition in the engine's cylinders.

• Common constituents in gasoline include: octane, iso-octane, and benzene, among others.
• Gasoline may also contain additives to enhance performance and prevent engine knocking.

By understanding these components, one can appreciate gasoline's efficiency in energy production and its critical role in transportation.

Kerosene Composition

Kerosene, another vital petroleum fraction, consists of hydrocarbons in the range of \( \mathrm{C}_{10} \) to \( \mathrm{C}_{15} \). It serves various purposes, notably as jet fuel and heating oil. The slightly heavier hydrocarbons in kerosene give it a higher boiling point than gasoline, making it less volatile.

This fraction includes alkanes, cycloalkanes, and aromatics similar to gasoline but with longer carbon chains, contributing to its reduced explosiveness compared to gasoline. Kerosene's stability makes it ideal for use in lamps and heaters, especially in regions where electricity might be less available.

• Kerosene often contains additives to improve storage life and performance.
• It is known for its relatively clean burn, making it an efficient heating source.

These characteristics reflect its versatility and widespread usage across different applications.

Lubricating Oil Composition

Lubricating oil, essential for reducing wear and friction in mechanical systems, is composed of hydrocarbons with carbon chains in the range of \( \mathrm{C}_{17} \) to \( \mathrm{C}_{20} \). These molecules are heavier and more viscous, which are critical properties for effective lubrication.
Lubricating oils comprise a mixture of mineral oils and synthetic oils, which may also contain a variety of additives. These additives can enhance properties like viscosity, thermal stability, and resistance to oxidation and corrosion.

• Base oils can be either mineral-based, derived from refining crude oil, or synthetic.
• Such oils aid in extending the life of machinery by minimizing overheating and bearing loads.

These characteristics make lubricating oils indispensable in the seamless operation of engines and industrial machinery.

Pitch and Asphalt Composition

Pitch and asphalt are very dense and heavy petroleum fractions, constituted by hydrocarbons with even longer carbon chains, primarily in the range of \( \mathrm{C}_{30} \) to \( \mathrm{C}_{40} \). Their heavy molecular weight gives them a solid or semi-solid state at room temperature, making them ideal for certain applications like road construction.
Asphalt is predominantly used in paving roads and making roofing materials, capitalizing on its durability and water resistance. Pitch, on the other hand, can be used in applications like waterproofing and sealing.

• The composition ensures high viscoelasticity, allowing it to handle stress and strain well.
• They are often mixed with aggregates to improve road surfaces' strength and longevity.

The unique composition and characteristics of pitch and asphalt make them critical materials in the construction and maintenance of infrastructure.