Question

Each of the following salts is 0.25 M. Please label them as acidic, basic, or neutral.

Sr(ClO₄)₂
RbBr
NaCN
Sr(OC₆H₅)₂
NH₄Cl
C₅H₅NHBr

Answer 1

a) Sr(ClO4)2

It is a salt of strong acid HClO4 and strong base Sr(OH)2. so the nature of the aqueous solution is neutral because there is no hydrolysis takes place.

Hence it is neutral

b) RbBr

It is a salt of strong acid HBr and strong base RbOH. so the nature of the aqueous solution is neutral because there is no hydrolysis takes place

Hence , it is neutral

c) NaCN

It is a salt of weak acid HCN and strong base NaOH. so the nature of the solution is basic due to anionic hydrolysis takes place.

NaCN ----------------- Na+ + CN-

H2O ------------------ H+ + OH-

         --------------------------------------

                            NaOH    + HCN

                        strong base    weak acid

                     ( more OH-)

Finally,

CN- + H2O ----------------- HCN + OH-

so the nature of the solution is basic.

d) Sr(OC6H5)2

This is a salt of weak acid C6H5OH and strong base Sr(OH)2, so the nature of the solution is basic due to anionc hydrolysis

C6H5O-   + H2O ------------------ C6H5OH + OH-

Hence the nature of the solution is basic.

e) NH4Cl]

It is a salt of strong acid HCl and weak base NH4OH, so, the nature of the solution is acidic due to cationic hydrolysis,

NH4+ + H2O ------------------ NH4OH + H+

Hence , the nature of the soltuion is acidic.

f) C5H5NHBr

It is salt of strong acid HBr and weak base C5H5N. so the nature of the solution is acidic due to cationic hydrolysis

C5H5NH+ + H2O ---------------- C5H5NHOH + H+

Hence the nature of the solutiion is acidic.