Question

All chemical reactions are:
A. Reversible
B. Irreversible
C. Exothermic
D. Endothermic

Answer 1

Hint: The type of chemical reaction depends upon the type of reactants and the surrounding conditions. With most of the reactants that occur, they are irreversible in nature. Chemical reactions do not have a generalised type of reaction.

Complete answer:
There is no correct answer to this question, but up to a certain extent we can say that all the chemical reactions are irreversible.
Chemical reaction is a reaction in which two or more reactants react with each other to give a product. There might also be cases where there is only one reactant giving another kind of product with the help of a catalyst.
The chemical reactions in which the reactants turn into products, but the product do not turn into reactants on its own, are called irreversible reactions. Most of the reactions are irreversible reactions that occur in nature.
The chemical reactions in which, reactants turn into products, but simultaneously the product also turn into reactants, are called reversible reactions.
The chemical reactions in which heat is released in the product side, and the reactants react on their own without giving any outside energy, are called exothermic reactions.
The chemical reactions in which we have to give energy from outside to the reactants so that reactions can occur are called endothermic reactions.
Now, when in an irreversible reaction, the product starts to turn into reactants due to certain favourable conditions, the reaction becomes reversible. In this reaction, the product will turn into reactants until equilibrium is reached. After equilibrium is reached, the reactants won’t turn into products and the products won’t turn into reactants.
There is no true answer to this question, because the conditions will decide the type of reaction. But, as even if a forced reaction is irreversible at the start of the reaction, we can say that all the chemical reactions are irreversible, but only up to a certain extent.

Note:
All the chemical reactions have their certain type and that certain type is decided by the surrounding conditions and the conditions that we apply to the reaction. Thus, we cannot say that all the chemical reactions are irreversible with all certainty.