Which one of the following is the correct sequence in increasing order of molecular weights of the hydrocarbons?
- AMethane, ethane, propane and butaneCorrect
- BPropane, butane, ethane and methane
- CButane, ethane, propane and methane
- DButane, propane, ethane and methane
Explanation
The correct sequence is determined by the number of carbon atoms in each hydrocarbon. These four gases belong to the alkanes group, where the molecular weight increases as more carbon and hydrogen atoms are added to the chain.
Methane has one carbon atom and is the lightest. Ethane has two carbon atoms. Propane has three carbon atoms. Butane has four carbon atoms and is the heaviest among the four.
The chemical formulas are Methane (CH4), Ethane (C2H6), Propane (C3H8), and Butane (C4H10). Since the number of atoms increases in this specific order, their molecular weights also increase accordingly. Therefore, option A is the correct sequence.
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