How a catalyst increases the rate of a reaction?

Answer 1

There are two ways in which catalysts work. You already know that when two different molecules bump into each other, they might react to make new chemicals. We usually talk about "collisions" between molecules, it would be much simpler to say that the molecules bumped into each other. How fast a chemical reaction is depends upon how frequently the molecules collide. You have probably been told about the "kinetic theory" which is all about heat and how fast molecules move around. What catalysts are doing when they make a chemical reaction go faster is to increase the chance of molecules colliding. The first method is by "adsorption", the second method is by the formation of intermediate compounds.

Adsorption This occurs when a molecule sticks onto the surface of a catalyst. Make sure that you spell this word correctly; it is not the same as absorption. Here is an example: it is possible to use Platinum as a catalyst to make sulphur Trioxide from Sulphur Dioxide and Oxygen. Sulphur Trioxide is very important because it is used to make Sulphuric acid which is needed for car batteries. The molecules of the two gases (Sulphur Dioxide and Oxygen) get adsorbed (stuck onto) the surface of a Platinum catalyst. Because the two molecules are held so close together, it is more likely that they will collide and therefore react with each other. The Sulphur Trioxide easily falls off the catalyst leaving space for more Sulphur Trioxide and Oxygen.

Intermediate Compounds Many catalysts, including all enzymes" work by forming intermediate compounds. What happens is very simple: the chemicals involved in the reaction combine with the catalyst making an intermediate compound, but this new compound is very unstable. When the intermediate compound breaks down it releases the new compounds and the original catalyst.

Answer 2

It changes the reaction pathway. The new pathway has lower activation energy. If the activation energy is lower, more collisions are more likely to be successful is changing the reactants to products.

Answer 3

Catalysts increase the rate of reaction by lowering the activation energy which is required for bonds to break. Because less energy is needed for a reaction to occur when catalysts are present, the reaction can take place quicker.

Answer 4

Many reactions require an initiating quantity of energy to start (gasoline doesn't burn until you put a match to it).

The function of catalysts in general is to reduce that "starting energy",

for example, allowing you to consume fuel (food) at body temperature.

Answer 5

A catalyst works by providing a different reaction route with a lower activation energy. The activation energy is the energy required to start the reaction happening, often by breaking some of the bonds in the reactants. Think of it like a journey from one valley to the next. The uncatalysed reaction is like going over a high pass, you have to climb up a long way in order to get down the other side. The catalyst allows you access to an easier route around the sides of the mountain or through a tunnel.

Answer 6

By providing an alternative pathway with a lower activation energy.

Answer 7

A Catalyst provides a good surface on which the reaction can occur so that the proportions are right and the Reaction speeds up.

Answer 8

A catalyst improve the yield of a chemical reaction and the reaction rate.

Answer 9

It does this by providing an alternate pathway for the reaction to occur, and this alternate pathway has a lower energy of activation than the original pathway.