Domestic energy basics: Liquefied Petroleum Gas (LPG) used for household cooking primarily consists of which hydrocarbon components under standard supply blends?
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Apropane and butane
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Bbutane and ethane
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Cmethane and ethane
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Dmethane and carbon monoxide
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Epropane and methane
Answer
Correct Answer: propane and butane
Explanation
Introduction / Context: LPG supplied for household cooking is a pressurized mixture of light hydrocarbons chosen for safe handling, suitable vapor pressure at ambient conditions, and clean combustion. Knowing its typical composition is standard refinery and utilities knowledge.
Given Data / Assumptions:
- LPG refers to bottled/cylinder cooking gas for domestic use.
- Typical climate: ambient temperatures where cylinders can vaporize normally.
- Commercial blends may vary seasonally but remain within conventional propane–butane ranges.
Concept / Approach: LPG is chiefly C3–C4 hydrocarbons (propane, butane, and isobutane). Methane is the main component of natural gas (piped PNG/CNG), not bottled LPG. Carbon monoxide is a toxic combustion product, not a fuel component.
Step-by-Step Solution:
1) Identify LPG family: liquefied alkanes with suitable vapor pressure—propane (C3H8) and butane (C4H10).2) Exclude methane-rich options: methane is not stored as LPG in domestic cylinders.3) Confirm safety/handling rationale: C3/C4 mixtures liquefy under moderate pressure and vaporize easily for stoves.Verification / Alternative check: Cylinder labels and national fuel standards specify propane–butane mixes (ratios tuned to season for vapor pressure control).
Why Other Options Are Wrong:
(b) Ethane is not a principal LPG cylinder component.(c) Methane and ethane describe natural gas mixtures, not LPG.(d) Carbon monoxide is a dangerous exhaust gas, not a fuel constituent.(e) Propane plus methane is not the standard LPG formulation.Common Pitfalls: Confusing LPG with PNG/CNG; methane dominance implies pipeline or compressed natural gas, not bottled LPG.
Final Answer: Propane and butane