Answer:
pH = 0.903.
Explanation:
Hello there!
In this case, according to the given information about the problem, we can notice there is a reaction between nitric acid and ammonia, whereas just the H ions from the former are relevant:
[tex]NH_3(aq)+H^+(aq)\rightleftharpoons NH_4^+(aq)[/tex]
Thus, we first calculate the consumed moles of ammonia, it order to evaluate the moles after the reaction:
[tex]n_{H^+}=0.020L*1.00mol/L=0.020mol\\\\n_{NH_3}=0.100L*0.050mol=0.005mol[/tex]
It means there is a leftover of moles of hydrogen ions of 0.015mol; then, we calculate the molarity of the resulting solution as follows:
[tex][H^+]=\frac{0.015mol}{0.120L}=0.125M[/tex]
Finally, we use the formula for the calculation of the pH to obtain:
[tex]pH=-log(0.125)\\\\pH=0.903[/tex]
Which means this solution is highly acidic.
Regards!
