Which one of the following molecules contains no $\pi$ bond?

The ionization enthalpy of $Na^{+}$ formation from $Na_{(g)}$ is $495.8 \ kJ \ mol^{-1},$ while the electron gain enthalpy of $Br_{(g)}$ is $-325.0 \ kJ \ mol^{-1}$. Given the lattice enthalpy of $NaBr_{(s)}$ is $-728.4 \ kJ \ mol^{-1}$. The energy for the reaction $Na_{(g)} + Br_{(g)} \rightarrow NaBr_{(s)}$ is $(-) \dots \dots \dots \dots \dots \times 10^{-1} \ kJ \ mol^{-1}$.

Identify the incorrectly matched set from the following:

Which of the following orders is not correct?

Assertion : Bond angle of $H_2S$ is smaller than $H_2O$.
Reason : Electronegativity of the central atom increases,bond angle decreases.

Which of the following molecules do not exist?