9A.4 Flashcards
what is a catalyst
it is a substance that increases the rate of reaction without being used up in the reaction (changing it chemically)
Catalysts dont provide lower activation energy of a reaction pathway it …
provides an alternative pathway with a lower activation energy
what is a reaction pathway
a reaction or a series of reacts that a reactant undergoes to convert to a product
how does a catalyst change the Maxwell-Boltzmann graph
it doesn’t change the graph just the activation energy moves up the graph (more area)
what is a reaction profile graph
it is a graph that has the same features as the enthalpy level diagram it just shows the activation energy
what is the difference between a profile diagram with and without a catalyst
the peek of the activation energy is lower
what is an intermediate
An intermediate is a molecule that is formed from two or more reactants and then reacts further to give products.
what is the reaction between peroxydisulfate ions and iodide ions
S2O8^2- (aq) + 2I^-(aq) ——–> 2SO4^2- + I2^-
what is the reaction between peroxydisulfate ions and iodide ions with an iron catalyst
reaction one:
S2O8^2-(aq) + 2Fe^2+(aq) ——-> 2SO4^-2(aq) + 2Fe^3+(aq)
reaction two:
2I^-(aq) + 2Fe^3+(aq) ———-> I2(aq) + 2Fe^2+(aq)
what are two economical benefits of using a catalyst
- the increase of the rate of chemical reactions, meaning more of the desired product
- reactions can take place at a lower temperature meaning less money spent as there a decrease in energy cost
when exams q asks us to compare two industrial processes what points should we include
- atom and yield economy
- energy coasts
- environmental issues
what are heterogeneous catalysts
catalysts that are in a different phase than the reactants
what is a phase
a physically distinct form of matter (liquid solid gas)
in chemical reactions what is considered waste
it is a product that has little to no commercial value
how can a catalyst help with reducing waste
- it stops any side reactions producing any unwanted products
- it helps with only forming the desired product with little to no co-product
how can a zeolite help in the manufacture of phenol
using a zeolite catalyst allows benzene to be oxidized to phenol using nitrogen monoxide with nitrogen as the only other product
which is better the manufacture of phenol, the use of zeolite with benzene for the use of cumene with benzene, and why
zeolite as a catalyst because more atom economy
what is zeolite
a catalyst made up form oxygen, silicon, and aluminum
Raney nickel is an
an alloy of nickel and aluminum
what are the advantages of using Rany nickel and HF as a catalyst for ibuprofen, instead of using AlCl3
- fewer steps from 6 to 3
- more atom economy
- HF and Raney nickel can be recovered and used more
what are other things to consider when comparing both Raney nickel and HF with AlCl3
- fewer steps less, most likely fewer energy coasts
- percentage yield for each step might be higher and it might be higher for fewer steps
- the whole process might be quicker so that you get more products
- there might be less product lost in separation after each step, and there might be only separation at the end