Question

what is a catalyst ? can anyone explain with example?

Answer 1

it's a substance that lowers the activation energy for a reaction to occur - which would otherwise occur at a slower rate or not at all - without being consumed.

An example of a catalyst? I like Shrock's catalyst used in olefin metathesis.

Answer 2

Does catalyst initiates the reaction mean it starts the reaction

Answer 3

well it would hold the reactant in a way that it would be (more) reactive, so i guess you could say that. Although some reactions take place without catalysts, so the statement could not be applied to all

Answer 4

but i heard that catalyst only alters the rate of reaction and will not initiate the reaction :)

Answer 5

there are some reactions that won't occur unless you introduce a catalyst

Answer 6

OK OK then what is different between catalyst and reagents

Answer 7

reagents are consumed, catalysts aren't

Answer 8

OK !!! What is energy of activation and how it is related to catalyst

Answer 9

can i tell you with enzymes, because i'm more comfortable talking about those

Answer 10

ok fine !!

Answer 11

well all in all, a catalyst holds molecules in place so that certain bonds are strained in order to make them weaker/more reactive, activation energy is energy needed to break old bonds, form new bonds and the rearrange things.

Answer 12

Metals are often catalysts because the can change the acidity or basicity of molecules allowing nucleo- or electrophiles to act on them

Answer 13

by polarizing their electrons

Answer 14

humnnn

Answer 15

in what physical form the catalyst will bee?

Answer 16

catalysts can be solid or liquid, I've never heard of ones in gaseous forms

Answer 17

they can be categorized into homogenous or heterogenous depending on which phases they are