1. Which of these compounds give out the most heat (per mole) on
combustion?
C6H14, C7H16, C8H18, C9H20, C10H22
Chose C6H14 because it's the most flammable.
2. Thought this question was way too easy. Too easy to be
questioned so I decided to check if my answer is correct. How many
electrons are found in the outer shell of each carbon atom in the
propane molecule? Isn't it still 4?
3. In a coal mine the percentage of methane in air is
continually monitored. Intially at 0 hour, there was slighlt below
5% of CH4. It steadily increases to 20% after 5 hours and also, at
the fifth hour, it plunged right down to 0% of methane.
What could have caused these changes to happen? Not really sure
of this question.
Guys, do help if possible. Thanks.
1)C10H22. it has the most number of C=C and C-H bonds, which
release the most energy when a single mol of the compound is
combusted.
C6H14 is the most flammable. nothing wrong with that. but being
easy to combust doesn't equate it to it giving the most energy.
2) the carbon atom in propane has now 8 electrons, due to
electron sharing with the hydrogen atoms to form a stable octet
structure.
3) High concentration of volatile methane gas led to explosion,
where all the methane gas are fully combusted, bringing the methane
level back down to 0%