Problem

Lewis acidity is about accepting electron pairs, not donating protons—so look for molecules with incomplete octets or empty orbitals that can form new bonds. Central atoms like $\text{Sn}^{2+}$ in $\text{SnCl}_2$ or $\text{C}$ in $\text{CO}_2$ have vacant orbitals ready to accept electrons, while $\text{NMe}_3$ is the opposite (a Lewis base with a lone pair to donate). Check each molecule's electron count and geometry to spot which ones are electron-deficient.

Lewis acidity is about accepting electron pairs, not donating protons—so look for molecules with incomplete octets or empty orbitals that can form new bonds. Central atoms like $\text{Sn}^{2+}$ in $\text{SnCl}_2$ or $\text{C}$ in $\text{CO}_2$ have vacant orbitals ready to accept electrons, while $\text{NMe}_3$ is the opposite (a Lewis base with a lone pair to donate). Check each molecule's electron count and geometry to spot which ones are electron-deficient.