2 quick chem question

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Why do geometric isomers only exist in the alkene family but not in alkanes?

What are different ways of increasing the rate of a chemical reaction?
 

DDS

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the double bond in the alkene alows for roation. Due to the rigidity of the double bond, molecules direclty in contact with the bond have a very hard time moving but the two free bonds on each molecule ( asuming its a two carbon chain) are albe to roate freely.

This condition is know as Cis and Trans isomerisim.

Also with more complex alkene there is more double bonds. Also the more complex the alkene, the more side chains it may have. Thus with a large amount of side chains, the chain itself can attach to either the Cis or Trans side of the double bond and thus producing a different molecule.

The alkanes on the other hand have no double bonds and no matter how you look at them , two molecules with the same chemical formula can not be rearranged differently


As for increasing the rate of chemical reaction you must:

  • increase surface area
  • increase concentrations
  • increase temperature
 
Last edited:
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thx that clears things up a bit...As for increasing the rate of chemical reaction are there any more ways or just those....
 
i think catalyst will increse the rate of rxn?? pls check
 
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neone else?
 
joejo said:
thx that clears things up a bit...As for increasing the rate of chemical reaction are there any more ways or just those....
Temperature and in some cases, the concentration of the reactants, depending on the order of the reaction (if you are unsure of what I'm talking about, just ignore it).

[edit]
sorry, i didn't read your whole post. And i don't think catalysts speed up the reaction, they simply allow it to occur at a lower energy state by lowering the activation energy.
 
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WhirlwindMonk said:
Temperature and in some cases, the concentration of the reactants, depending on the order of the reaction (if you are unsure of what I'm talking about, just ignore it).

[edit]
sorry, i didn't read your whole post. And i don't think catalysts speed up the reaction, they simply allow it to occur at a lower energy state by lowering the activation energy.
Lowering the activation energy is speeding up the reaction. Think of it in terms of a linear distance. If I am 5 miles from a store one day and 3 miles the next day, when will I get there faster?
 
bross7 said:
Lowering the activation energy is speeding up the reaction. Think of it in terms of a linear distance. If I am 5 miles from a store one day and 3 miles the next day, when will I get there faster?
That's right. It's just all those rules I have crammed into my head tend to get mixed up, especially when its almost 1 in the morning.
 

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