Question

What is the pH of a 6.2 x 10-2 mol/L solution of nitric acid?

Answer 1

`pH=-log_10[H_3O^+]=1.21`

Explanation:

`pH=-log_10[H_3O^+]`

We know that nitric acid is a moderately strong acid for which protonolysis of the water solvent is relatively complete, i.e. the given equilibrium lies to the right...........

`HNO_3(aq) + H_2O(l) rarr H_3O^+ + NO_3^-`

That is the solution is stoichiometric in `H_3O^+`.

And we simply take `log_10`............

`-log_10(6.2xx10^-2)=-(-1.207)=1.21`.

For more details, see this old answer.