Question

Which acts as Lewis base in the reaction, BCl3 + PH3 → [Cl3B→PH3]
a) PH3
b) BCl3
c) Both a) and b)
d) None​

Answer 1

Answer:

Lewis base is one which donates pair of electron and in our reaction PH3 is donating pair of electron to BCl3 soPH3 is a lewis base.

Answer 2

The correct answer is 'a'. In the reaction BCl₃+PH₃ → [Cl₃B → PH₃], PH₃ is the Lewis base.

We must first know what is Lewis base?

• In acid-base reaction when there is transfer of electron's pair  from base to acid, the substance that donate electrons is called Lewis base.
• Electron pair donor is  another name for Lewis base.
• Some examples are H₂0, OH⁻, CO, SO₄²⁻.

Thus, PH₃ donate electrons because it has nonbonding electrons and is called Lewis base whereas in BCl₃, boron is deficient in electrons thus it accept electrons and acts as Lewis acid.