Question

Consider the following data on some weak acids and weak bases: acid base b name formula name formula acetic acid HCH,CO2 1.8 x 10 ammonia NH, | 1.8 x 10" aniline CH NH, 4.3 x 100 hypochlorous acid HClO 3.0 x 10 Use this data to rank the following solutions in order of increasing pH. In other words, select a 'l' next to the solution that will have the lowest pH, a 2' next to the solution that will have the next lowest pH, and so on. solution 0.1 MC NH3C choose one 0.1 M Nacio choose one 0.1 M KNO3 choose one 0.1 M NH Br choose one X 5 ?

Answer 1

Answer

solution	pH
0.1M C6H5NH3Cl	1
0.1M NaClO	4
0.1M KNO3	3
0.1M NH4Br	2

Explanation

i) C6H5NH3Cl and NH4Br are salts of weak base and strong acid , so their solutions would be acid due to partial dissociation of conjucate acids , C6H5NH3Cl and NH4Br

C6H5NH3⁺ (aq) + H2O(l} <-------> C6H5NH2(aq) + H3O⁺(aq)

NH4⁺(aq) + H2O(l) <----------> NH3(aq) + H3O⁺(aq)

C6H5NH2 is less basic than NH3 , C6H5NH3⁺ is more acidic than NH4⁺

ii) KNO3 is a salt of strong acid and strong base , so the solution of KNO3 would be neutral

iii) NaClO is salt of weak acid and strong base ,so solution of NaOCl is basic due to partial hydrolysis of conjucate base OCl^-

OCl^-(aq) + H2O(l) <----------> HOCl(aq) + OH^-(aq)