option i) and ii) are the correct ones.
So, the very first two equations
NH3 (aq) + H2o → NH4+ (aq) + OH-
And
NH4+ (aq) + H2o → H3o+ + NH3 (aq)
Give the ionization form of water as a product.
The result of the ion concentrations in water is represented by the constant known as the ionic product. Water's ionic byproduct is referred to as Kw.
As the temperature rises, the value climbs, suggesting that the concentration of H+ and OH- ions grows as well.
The amount of hydronium and hydroxide ions present in water at any one time is almost unaffected by this minute ionization.
As a result, the concentration of undissociated water molecules is essentially constant at all times and can be referred to as a constant.
An equilibrium represents a state in a process when the observable properties such as color, temperature, pressure, concentration etc do not show any change.
The word equilibrium means ‘balance’ which indicates that a chemical reaction represents a balance between the reactants and products taking part in the reaction. The equilibrium state is also noticed in certain physical processes such as the melting point of ice at 0℃, both ice and water are present at equilibrium.
In the case of physical processes such as the melting of solid, dissolution of salt in water etc., the equilibrium is called physical equilibrium while the equilibrium associated with chemical reaction is known as chemical equilibrium.
The chemical equilibrium in a reversible reaction is the state at which both forward and backward reactions occur at the same speed.
The stage of the reversible reaction at which the concentration of the reactants and products do not change with time is called the equilibrium state.
Read More: Calculating Equilibrium Concentration
There are two types of chemical equilibrium:
In this type, the reactants and the products of chemical equilibrium are all in the same phase. Homogenous equilibrium can be further divided into two types: Reactions in which the number of molecules of the products is equal to the number of molecules of the reactants. For example,
Reactions in which the number of molecules of the products is not equal to the total number of reactant molecules. For example,
In this type, the reactants and the products of chemical equilibrium are present in different phases. A few examples of heterogeneous equilibrium are listed below.
Thus, the different types of chemical equilibrium are based on the phase of the reactants and products.
Check Out: Equilibrium Important Questions