Liquefied Petroleum Gas (LPG) supplied as a domestic and industrial fuel is primarily a mixture of which hydrocarbons?

Introduction:
LPG is a widely used portable fuel. Understanding its composition explains its storage as a liquid under moderate pressure, its combustion properties, and differences from natural gas and gasoline vapors.

Given Data / Assumptions:

• Application: domestic cooking, space heating, and industrial burners.
• Storage: pressurized cylinders/balls at ambient temperature.
• We seek the principal hydrocarbon constituents.

Concept / Approach:
LPG primarily contains C3 and C4 hydrocarbons—propane and butane (including isobutane). These liquefy easily at modest pressures, enabling compact storage and transport. Their volatility and clean-burning character suit household and light industrial uses. Composition may be seasonally adjusted (more propane in colder climates for better vaporization).

Step-by-Step Solution:
1) Distinguish LPG from natural gas: natural gas is mostly methane (C1).2) Recall LPG’s storage/pressure behavior consistent with C3–C4 vapors.3) Conclude that propane and butane are the main components.

Verification / Alternative check:
Fuel specifications worldwide (e.g., IS/EN/ASTM) define LPG grades by C3/C4 content with limits on impurities, odorant requirements, and vapor pressure ranges.

Why Other Options Are Wrong:
Methane/ethane: Describe natural gas/ethane-rich streams, not LPG.High-boiling olefins/naphthenes/aromatics: Not compatible with LPG definition or storage behavior.

Common Pitfalls:
Equating LPG with LNG (liquefied natural gas) or CNG; those rely on methane and very different storage conditions (cryogenic or high compression).

Final Answer:
Propane and butane