Question

arrange the solutions in order of increasing acid strength:

NH4Cl

NH3

H3BO3

Na2B4O7

C6H8O7

HCl

NaHCO3

NaOH

Answer 1

Ans :-

# Ka of H2B4O7 or H3BO3 = 5.8 x10-10

# Ka of H2CO3 = 4.3 x 10-7

# Ka of C6H8O7 = 7.2 x 10-4

# NH4Cl is the salt of weak base NH3 and strong acid HCl, therefore it is an acidic salt and have pH less than 7.

# Na2B4O7 is the salt of weak acid H2B4O7 and strong base NaOH, therefore it is a basic salt and have pH greater than 7.

# NaHCO3 is the salt of weak acid H2CO3 and strong base NaOH, therefore it is a basic salt and have pH greater than 7.

# NH3 is a weak base therefore its pH is more than 7

# HCl is strong acid therefore pH is less than 7.

# NaOH is strong base therefore pH is greater than 7.

# More the value of Ka stronger will be the acid.

Therefore,

The order of increasing acid strength is : HCl < NH4Cl < C6H8O7 < H3BO3 < NH3 < NaHCO3 < Na2B4O7 < NaOH