rank the following compounds according to their heat of combustion. compound compound name heat of…
rank the following compounds according to their heat of combustion. compound compound name heat of combustion 2 - methylheptane select 4 (highest) 3 2 1 (lowest) 2 - methylhexane select nonane select octane select
Answer
Explanation:
Step1: Understand heat - of - combustion principle
The heat of combustion of hydrocarbons generally increases with the number of carbon atoms. For isomers, the more branched - out isomer has a lower heat of combustion due to greater stability.
Step2: Count carbon atoms
2 - methylheptane has 8 carbon atoms, 2 - methylhexane has 7 carbon atoms, nonane has 9 carbon atoms, and octane has 8 carbon atoms.
Step3: Compare non - isomers first
Nonane has the most carbon atoms among them, so it has the highest heat of combustion (rank 4). 2 - methylhexane has the fewest carbon atoms, so it has the lowest heat of combustion (rank 1).
Step4: Compare isomers
Between 2 - methylheptane and octane (both with 8 carbon atoms), 2 - methylheptane is branched, so it is more stable and has a lower heat of combustion than octane. Octane ranks 3 and 2 - methylheptane ranks 2.
Answer:
2 - methylheptane: 2 2 - methylhexane: 1 Nonane: 4 Octane: 3