Question

Name the two barriers for a chemical reaction to occur.

Answer 1

Hint : For a chemical reaction to occur, there are some conditions to be satisfied by the reactant molecules. These conditions are related to the energy they possess, and the collision that takes place between them.

Complete Step By Step Answer:
A chemical reaction is a process in which one substance changes to another in a chemical transformation. Every reaction has its own rate that it proceeds in. Some reactions proceed faster than the others. There are a number of factors that can be a reason for this difference in rates. A major factor is the activation barrier.
An activation barrier is a barrier relating to energy that a chemical reaction must overcome to produce a chemical transformation of the reactants to form products. It is essentially a hurdle that the reactant molecules must bypass in order to form products.
The two barriers for a chemical reaction to occur are: activation energy and effective collision of reactant molecules.
Activation energy is the minimum amount of energy that the reactant molecules must possess in order to transform into corresponding products in a chemical reaction. It is different for every reaction, depending upon the nature of reactants and the presence of catalysts.
An effective collision is said to take place between two reactant molecules when they collide while possessing sufficient energy and with proper orientation. This is important, considering if the reactant molecules do not undergo an effective collision, the bonds between them will not break effectively so as to form the products.

Note :
Activation energy is affected by factors such as the nature of reactants and the presence of catalysts: Reactants that are covalent compounds need higher activation energy than those that are ionic compounds. Catalysts only speed up the rate of a reaction by providing alternative paths to proceed, and do not chemically affect the reactants in any way.