Which one of these salts will form a basic solution on dissolving in water?

a. nacl

b. kcn

c. nano3

d. nh4no3

e. fecl3

KCN forms a basic solution (option B)

Explanation:

Step 1: Data given

Acids have form AH, with conjugate base A-.  

Bases have the form BOH, with conjugate acid B+.

Strong acids have weak conjugate bases

Strong bases have weak conjugate acids

Weak acids have strong conjugate bases

Weak base have strong conjugate acids

a)  NaCl.

Na+ is a conjugate acid of NaOH, what is a strong base.

Cl- is the conjugate base of HCl, what is a strong acid.  

They form a neutral solution

b)  KCN.

K+ is a conjugate acid of KOH, what is a strong base.  

CN- is the conjugate base of HCN, what is a weak acid.  

K+ is a weak conjugate acid, CN- is a stronger conjugate base

They form a basic solution

c)  NaNO3.  

Na+ is a conjugate acid of NaOH, what is a strong base.

NO3- is the conjugate base of HNO3 , what is a strong acid.  

They will form a neutral solution

d)  NH4NO3.

NH4+ (ammonium) is the conjugate acid of NH3,  what is a moderately strong base.  

NO3- is the conjugate base of HNO3, what is a strong acid.

Ammonium is a stronger conjugate acid, nitrate is a weak conjugate base.

The solution is acid.

e) FeCl3 is an acid salt because Fe(OH)3 is weak base and HCl is a strong acid. pH is less than 7.

Fe^3+ is the conjugate acid of Fe(OH)3, what is weak base.

Cl- is the conjugate base of HCl, what is a strong acid.  

Fe^3+ is a 'stronger' conjugate acid, Cl- is a weaker conjugate base.

They solution is acid