Hello,

In some reactions, the rate is apparently independent of the reactant concentration. The rates of these zero-order reactions do not vary with increasing nor decreasing reactants concentrations. This means that the rate of the reaction is equal to the rate constant,  k , of that reaction. This property differs from both first-order reactions and second-order reactions.

A first-order reaction is a reaction that proceeds at a rate that depends linearly on only one reactant concentration.

Thanku.

Hello student,

• A reaction that depends on the concentration of only one reactant (a unimolecular reaction). Other reactants can be present, but each will be zero-order. A first-order reaction depends on the concentration of only one reactant. As such, a first-order reaction is sometimes referred to as a unimolecular reaction. While other reactants can be present, each will be zero-order, since the concentrations of these reactants do not affect the rate. Rate:−d[A]/dt=k[A]
• Zero order reaction is a kind of reaction whose rate always remains constant irrespective of the amount of reactant or product or catalyst or solvent present.It is always a complex reaction, i.e. it gets completed in multiple steps.Rate law: r= k[reactant]^0

Cheers!