Addition of 6 m hcl to which substance will not result in gas evolution?
(a) al
(b) zn
(c) k2co3
(d) nano3

the answer is d but can someone explain how to get that answer, ?

The correct answer is Option D.

Explanation:

The reaction of HCl with every substance given in the option follows the equations:

The reaction of aluminium with hydrochloric acid produces aluminium chloride and hydrogen gas. The equation follows:

Thus, this substance evolve gas on reaction.

The reaction of zinc with hydrochloric acid produces zinc chloride and hydrogen gas. The equation follows:

Thus, this substance evolve gas on reaction.

The reaction of potassium carbonate with hydrochloric acid produces potassium chloride, water and carbon dioxide gas. The equation follows:

Thus, this substance evolve gas on reaction.

The reaction of sodium nitrate with hydrochloric acid produces sodium chloride and nitric acid. The equation follows:

Thus, this substance will not evolve gas on reaction.

Hence, the correct answer is Option D.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.