For the reaction: A + H 2 O ⟶ B , rate ∝ A . What is its molecularity?

The molecularity of a reaction is defined as the number of reacting molecules which collide simultaneously to bring about a chemical reaction. In other words, the molecularity of an elementary reaction is defined as the number of reactant molecules taking part in the reaction. The molecularity of the given reaction is 2 .

For the reaction: A + H 2 O ⟶ B , rate ∝ A . What is its order of reaction?

The order of reaction can be defined as the power dependence of rate on the concentration of all reactants. For example, the rate of a first-order reaction is dependent solely on the concentration of one species in the reaction. The rate of the given reaction depends on only one reactant, A . So, the order of the reaction is 1 .

For a reaction A ⟶ B , the rate of reaction can be denoted by - dA dt or + dB dt . State the significance of plus and minus signs in this case.

The minus sign indicates the concentration of the reactants decreases at the given time. The plus sign indicates the concentration of the products increases at the same time of the chemical reaction. This can be used to represent the rate of the chemical reaction.