The factors that affect the rate of a reaction are:
- <em>nature of the reactant</em> - when reactants with different chemical composition are exposed to same conditions they would react differently. For instance, when an acid or base is added on litmus paper, blue litmus paper turns red in presence of acid while red litmus paper turns blue when base is added.
- <em>surface area</em>- a compound with small pieces spread over a large area will react faster than a big lump of a compound occupying a small area.
- <em>temperature of reaction</em>- reactants would react faster at high temperatures. this is because they have higher kinetic energy to collide with each other. Hence a plate of food on the table spoils faster than a plate of food in the fridge.
- <em>concentration</em>- an increase in concentration leads to more molecules available to collide and form products. An example, when you add more of indicator in a solution, the color becomes more clear since more particles react to give more color.
- <em>presence of a catalyst</em>- a catalyst lowers the activation energy, which means less energy is required to shift reaction in forward direction. In the presence of iron (Fe) a catalyst, nitrogen N₂ and hydrogen H₂ react to produce NH₃
The combination of the of two or more elements is known as a compound.
A homogenous mixture has a uniform composition all throughout. They are
similar in terms of the amount of composition present in a solution. For
example, oxygen is diatomic, O2. So oxygen is a compound because it has 2
elements combined in it. It is also a homogenous mixture if there are a lot of
O2 gases present in let’s say tank. They only differ in the place where they
are present. A compound is a representation of one molecule whereas a
homogenous mixture is present in a a solution.
