# 15 Facts on H2SO3 + K: What, How To Balance & FAQs

Potassium(K), an alkali metal, is highly reactive, and H2SO3 (sulphurous acid) is a weak inorganic acid. Let us examine their reaction in detail.

K is a soft, silvery-white metal, solid at room temperature, and is an excellent conductor of electricity. Its reaction with water is violent and highly exothermic. H2SO3 is a colorless and corrosive acid, with a pungent-burning sulphur smell. K is a good reducing agent, as seen in its reaction with H2SO3.

In this article, let us discuss the reaction of H2SO3 + K, the type of reaction, the forces involved, buffer solution, and other related facts.

## What is the product of H2SO3 and K?

Potassium sulphite and hydrogen gas are the products formed when H2SO3 reacts with K.

H2SO3 + 2K ———> K2SO3 + H2

## What type of reaction is H2SO3 + K?

H2SO3 + K is a single displacement reaction.

## How to balance H2SO3 + K?

The equation H2SO3 + K is balanced by the following steps.

H2SO3 + 2K = K2SO3 + H2

• Identify and count the number of moles of each element involved in both the sides of the reaction.
• We find that the number of moles of all elements in the reactant and product side are equal except potassium (K).
• A coefficient of 2 is added before K in the reactant side so that the number of moles of K are same on both sides of the equation.
• The overall balanced equation is given by –
• H2SO3 + 2K  = K2SO3 + H2

## H2SO3 + K titration

H2SO3 + K will not undergo titration as K being a metal, will not be used in the titration.

## H2SO3 + K net ionic equation

The net ionic equation between H2SO3 + K is:

H2SO3 (aq)+ K (s) = 2K+  (aq) + SO32- (aq) + H2 (g)

The following are the steps to derive the net ionic equation:

• Write the balanced molecular equation along with its physical state.
• H2SO3 (aq) + K (s)  =  K2SO3 (aq)  + H2 (g)
• The electrolytes, which are strong, are split into their respective ions. H2SO3 is a weak electrolyte, K is a solid and H2 is a gas, so will not split. The equation now becomes,
• H2SO3 (aq)+ K (s) = 2K+  (aq) + SO32- (aq) + H2 (g)
• The charge in the above equation is also conserved. Therefore, the net ionic equation is –
• H2SO3 (aq)+ K (s) = 2K+  (aq) + SO32- (aq) + H2 (g)

## H2SO3 + K conjugate pairs

• Conjugate base of H2SO3 as HSO3
• K is a metal, so there is no conjugate pair for K.

## H2SO3 + K intermolecular forces

• In H2SO3, Electrostatic forces, London dispersion forces, Van der Waals forces, and dipole-dipole interactions are the intermolecular forces that hold the hydrogen and sulphite ions together.
• Metallic bonding is seen in K, as it is a metal.

## H2SO3 + K reaction enthalpy

H2SO3 + K reaction enthalpy is -467.87 KJ/mol. The enthalpy of the reaction is calculated using the values listed below,

• The enthalpy of formation of elements or molecules existing in their original state is taken as zero.
• ∆Hf°(reaction) = ∆Hf°(products) – ∆Hf°(reactants)

= -1123.37 – (-655.5)

= -467. 87 KJ/mol

## Is H2SO3 + K a buffer solution?

H2SO3 + K will not form a buffer solution due to the presence of a metal (K) and weak sulphurous acid.

## Is H2SO3 + K a complete reaction?

H2SO3 + K  is a complete reaction since one of the products formed is hydrogen gas that gets evolved during the reaction.

## Is H2SO3 + K an exothermic reaction?

H2SO3 + K is an exothermic reaction, as the reaction enthalpy is found to be negative.

## Is H2SO3 + K a redox reaction?

H2SO3 + K is a redox reaction where,

• Potassium is oxidized from 0 to +1 oxidation state.
• Hydrogen is reduced from +1 to 0 oxidation state.

## Is H2SO3 + K a precipitation reaction?

H2SO3 + K is not a precipitation reaction as the product formed is completely soluble in water, and no precipitate is observed.

## Is H2SO3 + K an irreversible reaction?

H2SO3K is an irreversible reaction as the forward reaction is more favorable due to increased entropy associated with the liberation of gaseous hydrogen.

## Is H2SO3 + K a displacement reaction?

H2SO3 + K  is an example of a single displacement reaction, as potassium is more reactive than hydrogen and will displace it from its salt solution to form potassium sulphite.

Conclusion

The reaction of K with H2SO3 is less violent than with H2SO4, as sulphurous acid is a weak acid. The reaction proceeds with a violet-colored flame. Potassium is a very vital nutrient for human and plant growth.