Question

Consider the following data on some weak acids and weak bases: acid name hydrofluoric acid formula HF 6.8 x 10-4 base name formula hydroxylamine HONH2 1.1 x 10-8 ammonia NH, 1.8 10-5 hydrocyanic acid HCN 4.9 x lo-10 Use this data to rank the following solutions in order of increasing pH. In other words, select a 'l' next to the solution tha the solution that will have the next lowest pH, and so on. solution PH 0.1 M HONHJCI choose one 0.1 MKF choose one: 0.1 M NaNO3 choose one 0.1 M NACN choose one XS ?

Answer 1

HONH3+ is conjugate acid of HONH2

So, its pH would be less than 7

F- is conjugate base of HF

So, its pH would be more than 7

NaNO3 is neutral salt.

So, its pH would be 7

CN- is conjugate base of HCN

So, its pH would be more than 7

CN- is stronger base as compared to F- because Ka of HF is more.

So, pH of CN- will be more than pH of F-

Answer:

HONH3Cl: 1

HF: 3

NaNO3: 2

HCN: 4