Question

Which of the following contains a coordinate covalent bond ?

• A. $N_2H^+_5$
• B. $BaCI_2$
• C. $HCl$
• D. $H_2O$

Answer 1

Answer: (A)

$N_2H^+_5$

Answer 2

$N _{2} H _{5}^{+}$is formed from $N _{2} H _{4}$ which has a lone pair of electrons on '$N$' and positive charge on '$H$' takes away its electron and to complete duplet, a co-ordinate bond is present from $N$ to $H$. $H _{4} N _{2}+ H ^{+} \rightarrow\left[ H _{4} N _{2} \rightarrow H \right]^{+}$