Indicate whether or not each of the following ionic compounds will undergo hydro
ID: 538103 • Letter: I
Question
Indicate whether or not each of the following ionic compounds will undergo hydrolysis and predict whether the resulting solution pH will be acidic, basic, or indeterminate (both ions undergo hydrolysis).
(a) PbI2 acidic hydrolysis basic hydrolysis indeterminate hydrolysis no hydrolysis
(b) BeS acidic hydrolysis basic hydrolysis indeterminate hydrolysis no hydrolysis
(c) Al(NO3)3 acidic hydrolysis basic hydrolysis indeterminate hydrolysis no hydrolysis
(d) CsI acidic hydrolysis basic hydrolysis indeterminate hydrolysis no hydrolysis
Explanation / Answer
a. Lead II iodide is a salt of weak base, lead II hydroxide and strong acid, HI. When dissolved in water the pb2+ ion hydrolyse in water forming weakly dissociated lead hydroxide and H+ ions. Hence the solution is acidic.
b. BeS being the salt of weak base Beryllium hydroxide and weak acid, H2S, the PH is indeterminable.
Cc. Al(NO3)3 It is the salt of weak base aluminum hydroxide and strong nitric acid. Thus aluminum ions hydrolyse in water to form weakly dissociated hydroxide and H+ ions rendering the solution acidic PH.
d. CsI It is the salt of strong acid HI and strong base CsOH. Neither ions hydrolyse hence the solution will be neutral.