Cracking and Catalysts

what is a catalyst?

a substance that in creases the rate of reaction without being used up, providing an alternate route for the reaction with lower activation energy.

what is a homogenous catalyst?

catalyst in the same physical state as the reactants

what is a heterogenous catalyst?

catalyst in a different physical state to the reactants (normally gas reactants, solid catalyst)

what is the process for heterogenous catalysts?

the reactants adsorb onto the catalyst, weakening the reactant bonds which then break and new bonds are formed and the products are released.

what is a catalyst poison?

a substance that stops a catalyst functioning properly e.g. substance absorbing more strongly to catalyst surface than the reactants can.

what is cracking?

breaking down a larger molecule into smaller ones via steam or catalytic cracking

what is steam cracking?

cracking with steam and a temperature over 800 C

what is catalytic cracking?

the hydrocarbon vapour is over a heated catalyst with zeolite and temperatures over 550 C