Question

5. Write an acid-base equation for the following pairs of compounds: a. HF and HCI b. NaOH and NH3 C. HCl and NaOH d. CH3COOH and NH3 e. NH4CI and NH3

Answer 1

a) HCl and HF both are acids.

Hence there is no reaction between these two compounds.

But HCl is stronger acid than HF. Hence in presence of HCl, there is no dissociation of HF due to common ion effect.

HCl ------> H⁺ + Cl^​​​-

There exists an equilibrium between proton and fluoride ion in case of weak acid where as strong acid dissociates completely.

HF <--------> H⁺ + F^-

b)

NaOH and NH_{​​​​​3} are both are bases. Hence there is no reaction between them.

NaOH is a stronger base than Ammonia. Hence NaOH dissociates completely where as in Ammonia, there exists an equilibrium between ammonium ion and OH^{​​​​​-} ions.

c) Neutralization Reaction between HCl(acid) and NaOH (base) forms a salt (NaCl) and water.

HCl + NaOH -------> NaCl + H_{​​​​​​2}​​​O

d) Neutralization Reaction between Ammonia (weak base) and acetic acid (weak acid) can be written as

CH₃COOH + NH_{​​​​​3} (aq) ------- > CH₃COONH4 + H₂O

f)

Ammonium chloride is a salt and Ammonia is a base. Hence no acid base reaction.

But in the presence of Ammonium chloride, dissociation of ammonia decreases due to common ion effect.