Choose the correct order for the given property.
$M.P. \to$ Melting Point; $S \to$ Solubility

Considering ethene molecule,which of the following statements is/are correct?
$I$. $C-C$ bond is formed by overlapping of $sp^2-sp^2$ hybrid orbitals.
$II$. $C-H$ bond is formed by overlapping of $sp^2-s$ orbitals.
$III$. $p\pi-p\pi$ bond is present.
$IV$. $H-C-H$ bond angle is greater than $H-C-C$ bond angle.
$V$. Nodal plane of $\pi$ bond and molecular plane are same.

In the reaction $SnCl_2 + 2Cl^{-} \to SnCl_4$,the Lewis acid is:

Which of the following is the correct increasing order of $O-O$ bond length in $O_2$,$O_3$,and $H_2O_2$?

During the formation of a chemical bond,

The formation of $PH_4^+$ is difficult compared to $NH_4^+$ because