Question

Which is not the Lewis acid ?

• A. $H_{2}O$
• B. $A{g}^{+}$
• C. $B{F}_3$
• D. $ZnC{l}_2$

Answer 1

Answer: (A)

$H_{2}O$

$H_{2}O\to$No vacant orbitals so it cannot accept an electron pair. Whereas in $B{F}_3,Z{n}^{2+},A{g}^{+}\to$vacant orbitals are present, so they can accept electron pair and act as Lewis acid.
$\therefore H_{2}O$, not a lewis acid.