Usually none.
Using catalysts the activation energy is lowered.
Catalysts decrease activation energy.
Catalysts doesn't affect the energy of reactions
Catalysts help chemical reactions: the activation energy is lowered, the reaction rate is accelerated. Catalysts are not exhausted in the reaction and are recyclable.
Catalysts lower the activation energy of reactions, usually by providing an alternate reaction pathway, or mechanism that does not require so much energy. Having a lower activation energy means that less energy has to be transferred to each molecule in order for the reaction to progress.
Sometimes, catalysts are needed. ---------------- An optimal level of the activation energy.
Regardless of how much energy is ultimately created or used up by a chemical reaction, a certain amount of energy called the activation energy must first be invested to start the reaction. Catalysts help chemical reactions occur by lowering this activation energy, allowing for the reaction to occur far more frequently and require less energy in the short run. Catalysts are never exhausted when used in this way, so they can be used over and over to facilitate numerous consecutive reactions occur.
They lower the activation energy required for the reactions to take place
Catalysts greatly reduce the amount of activation energy needed to begin a reaction.
Catalysts increase the speed of a reaction without taking place in the reaction themselves. This is very useful in industry as it means that chemicals can be made much faster through usually slow chemical reactions, and as the catalysts don't take part in the reaction themselves, they can be reused as much as its needed. Examples of catalysts in industries include the use of the biological catalysts enzymes to brake down substrates in baby foods into smaller simpler molecules. Catalysts lower the activation energy required for a reaction to occur. This will mean that more molecules will have the energy to react. Catalysts allow equilibrium to be established quicker. Catalysts in general lower reaction temperatures leading to lower production costs. Catalysts add to cost e.g. palladium in catalytic converters. Catalysts can be poisoned by waste products eg. Sulphur in petrol and oil can reduce the properties of catalytic converters.
Catalysts lower the activation energy required for a chemical reaction, allowing reactants to convert into products more easily and quickly. They provide an alternative reaction pathway that requires less energy, but they do not alter the overall energy of the reactants or products. By facilitating the reaction, catalysts increase the reaction rate without being consumed in the process.
They lower the activation energy required for the reactions to take place