Question

Give two examples each of reversible and​

Answer 1

Answer:

Reversible changes - where a change is made physically and can be undone or reversed. For example: freezing water to make ice. Irreversible changes - where the change is made chemically and can't be reversed into its original states. For example: baking a cake.

Answer 2

Answer:

Reversible Changes

Any changes which can be reversed or are a temporary conversion are known as reversible changes. The reactions which are reversible are called reversible reactions. In this reaction, one substance is modified into another form but a new compound is not formed. Processes such as melting, boiling, evaporation, freezing, condensation, dissolution are reversible changes. Few examples are melting of wax, freezing of ice, boiling water which evaporates as steam and condenses back to water.

Reactions are an interaction of two or more compounds called reactants to produce a product(s). In a reversible reaction, reactants and products formed are connected by a two-way arrow (⇌). This means reactants can be obtained back from the products.

Consider the reaction below,

A +B ⇌ C + D

Here, A and B are two reactants which react to give C and D. The two-headed arrow indicates that reaction is reversible and the reactants, A and B can be obtained from C and D.

Irreversible changes

In contrast to reversible changes, irreversible changes are permanent changes. Reactants react to form an entirely new compound and cannot be reversed. Heating, burning, mixing, powdering are few processes which cause irreversible changes. A common observable example is the cooking of raw egg which can’t be converted back to its original form. Ash obtained by the combustion of paper or any other substances is another example.

When a reaction is taking place in a unidirectional way such reactions are called irreversible reactions. In such reactions in a period of time reactants react completely to form a product. Here reaction is denoted by a one-way arrow (→).

For example,

A → B +C

Here, A is the reactant which is completely converted into products B and C which do not react to form A.