Nitric acid (HNO3) is used in the production of fertilizer, dyes, drugs, and explosives. Calculate the pH of a HNO3 solution having a hydrogen ion concentration of 0.71 M.

pH of HNO₃ having an hydrogen ion concentration of 0.71M is 0.149

Explanation:

HNO₃ (aqueous) ⇄ H⁺ + NO3⁻

The pH is defined as the negative log of the hydrogen ion concentration

pH = - log [H⁺]

From the question, the hydrogen ion concentration is given as 0.71M, therefore

pH = -log [0.71]

     = 0.149

0.15

Explanation:

Whenever we are asked to calculate the pH of a particular solution in Chemistry it means that we are to look for its degree of acidity or basicity of such solution. Since the question is about an acidic solution, that is HNO3 we are to find the degree of acidity in the solution.

Therefore, the formula for the pH of a solution is given below;

pH = - log [ H^+].

In the question, we are given the hydrogen ion concentration to be = 0.71 M.

Hence, pH = - log [0.71].

pH = 0.14874165128092471.

pH =0.15.

It means that the solution is very acidic.

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.