What is the pH for the solution made from 11.10 mL of 0.278 M HCl solution mixed with 70.90 mL of 0.1300 M ammonia solution ? Note that the pKa for NH4+ is 9.241


8.94
9.24
8.77
9.72
9.54

2 answers

hey i found the working to this somewhere else and it was

its a buffer so
pH=pKa + log[base]/[acid]

=9.241 + log [70.9x.1300]/[11.1x0.278]

= 9.72

which makes sense but...
i also had that question on my assignment and got it wrong

the actual answer is 9.54
i cannot find a reason for this but as we were told not to use that eqn in chem then there must be another way to do it
calculate the percent composition for NaOH and the tell how many grams of each elements are in a 14 gram sample.