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.

The decreasing order of bond angles in $BF_3$,$NH_3$,$PF_3$ and $I_3^-$ is

In the Lewis dot structure of carbonate ion shown,the formal charges on the oxygen atoms $1, 2,$ and $3$ are respectively:

$A$ tin chloride $Q$ undergoes the following reactions (not balanced):
$Q + Cl^{-} \rightarrow X$
$Q + Me_3N \rightarrow Y$
$Q + CuCl_2 \rightarrow Z + CuCl$
$X$ is a monoanion having pyramidal geometry. Both $Y$ and $Z$ are neutral compounds. Choose the correct option$(s)$.
$(1)$ The central atom in $X$ is $sp^3$ hybridized
$(2)$ The oxidation state of the central atom in $Z$ is $+4$
$(3)$ The central atom in $Z$ has no lone pair of electrons
$(4)$ There is a coordinate bond in $Y$

In the reaction $LiH + AlH_3 \to LiAlH_4$,$AlH_3$ and $LiH$ act as:

Arrange the following in the decreasing order of their bond enthalpy: $H_2, O_2, N_2$.