Question

The reaction between a base and metal will be vigorous or not depends upon:
A. Smaller the difference between the metals in the reactivity series, higher is the rate of reaction.
B. Larger the difference between the metals in the reactivity series, higher is the rate of reaction.
C. Depends on reaction pressure
D. Depends on temperature.

Answer 1

Hint: Think about when a metal reacts with a base, it forms corresponding salt along with the evolution of hydrogen gas and the reaction between a base and metal will be vigorous or not depending on the position of metal in reactivity series.

Complete step by step solution:
- We know that that the reactivity series is a series of metals, in order of reactivity from highest to lowest. Reactivity of a metal is based on how readily it will react with any given reagent and how many types of reactions it can undergo. Thus, the most reactive metal is placed at the top of the series whereas the least reactive metal is placed at the bottom.
- The reactivity series allows us to predict the results or observation of a reaction. It is used to summarize the information about the reactions of metals with acids, bases, water and double displacement reactions.

- The reactivity series is:
\[K > Na > Ca > Mg > Al > Zn > Fe > Sn > Pb > Cu > Ag > Au > Pt\]

- The reactivity of metals is due to the difference in the stability of their electronic configurations as atoms or ions. The more stable atoms are less reactive and the other strive to become stable by reacting with different molecules, which makes them more reactive.
- Here, we know that when a base reacts with metal then corresponding salt is formed along with the evolution of gases and also, larger the difference between metals in reactivity series, higher is the rate of reaction.
- The greater the difference between the stability of the molecules, the more vigorously they will react to achieve stability. If the difference between stability is less than the atoms will have a similar stability whether they react or not. Thus, they will not react as vigorously to become stable.

Hence, the correct answer is B. Larger the difference between the metals in the reactivity series, higher is the rate of reaction.’

Note: Although increased temperature and pressure may increase the speed of the reaction, the relative change will be unnoticeable when considered in context with the change in rate due to difference in reactivity.
- It should be remembered to you that in reactivity series, metals present at the top of the series can lose electrons more readily to form ions and corrode or tarnish more readily.
- They require more energy to be separated from their ores and become stronger reducing agents while metals at the bottom of the series are good oxidizing agents.