The rate constant decreases.
The Arrhenius equation is: Ea = -RT ln(k/A) where Ea - activation energy R - universal gas constant ln - logarithm k - speed constant T - temperature in kelvins
if a reaction is carried out at constant temperature to completion it will have a zero activation energy.
The catalyst decrease the needed activation energy.
the speed will make the kinetic energy smaller.
Because the concentration is directly proportional to the rate of reaction (the rate will increase but k will remain the same), with an increase in concentration the activation energy will stay because the activation energy does not account for the concentration.
the energy decreases
The activation energy is lower and the reaction rate increase.
Technically, it isn't "heat" that makes a chemical reaction happen. "Heat" is merely the flow of energy from one place to another. It is the energy itself that causes a reaction to occur. As an increase in temperature occurs, there is an increase in the energy in a group of molecules by making them mover around faster and bum into each other more. This energy is called "Activation energy", and is defined as the amount of energy required to make the reaction start and carry on spontaneously. Higher activation energy implies that the reactants need more energy to start than a reaction with a lower activation energy. With that being said, activation energy is the answer
decrease
Catalysts decrease activation energy.
In an endothermic reaction the energy of the products is higher than the energy of the reactants. The activation energy also is an energy increase. The activation energy must be at least as high as the products energy or the reaction would never take place. Thus, the activation energy must be at least as large as the enthalpy in an endothermic reaction.
Temperature and activation energy