${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl} \underset{ }{\overset{{\mathrm{AgNO}}_2}{\to }} \mathrm{X} \left(\mathrm{major}\right);$
${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl} \underset{ }{\overset{\mathrm{KCN}}{\to }} \mathrm{Y} \left(\mathrm{major}\right);$
Number of dative bonds in X and Y are respectively

Chemistry Problem: Number of Dative Bonds in X and Y

First Reaction: C₂H₅Cl + AgNO₂ → X (major)

• AgNO₂ provides the NO₂⁻ ion which is ambident (can bond through N or O).
• With AgNO₂, the alkyl group attaches usually through oxygen, yielding ethyl nitrite (C₂H₅ONO).
• Structure of X: Ethyl nitrite (C₂H₅ONO).
• In ethyl nitrite, a dative bond exists between oxygen and nitrogen in the ONO group.
• Number of dative bonds in X: 1

Second Reaction: C₂H₅Cl + KCN → Y (major)

• KCN provides CN⁻ ion, which nucleophilically attacks via carbon.
• The product is ethyl cyanide (C₂H₅CN).
• There are only normal covalent bonds between C, H, and N atoms, no dative bonds.
• Number of dative bonds in Y: 0

Final Answer

The number of dative bonds in X and Y are respectively 1 and 0.