Question

Which of the given molecule contains double covalent bond?

• A. $H_{2}O$
• B. $CC{l}_4$
• C. $N{H}_3$
• D. $C_2{H}_4$

Answer 1

The correct option is D $C_2{H}_4$

In a molecule of $N{H}_3$, one nitrogen atom shares one electron each with 3 hydrogen atoms and forms 3 single covalent bonds.
Similarly, $H_{2}O$ is formed by 2 single covalent bonds between 1 oxygen atom and 2 hydrogen atoms and $CC{l}_4$ is formed by 4 single covalent bonds between 1 carbon atom and 4 chlorine atoms.
But in the case of $C_2{H}_4$, 4 single bonds are formed by hydrogen atoms with carbon atoms. But there is a double bond between the two carbon atoms, which completes the octet of the carbon.
Hence, the correct option is b) $C_2{H}_4$.