Calculate the standard enthalpy change for synthesis of ammonia gas from following data.

i. $\quad 2 \mathrm{H}_{2(\mathrm{~g})}+\mathrm{N}_{2(\mathrm{~g})} \longrightarrow \mathrm{N}_2 \mathrm{H}_{4(\mathrm{~g})} ; \Delta_{\mathrm{r}} \mathrm{H}_1^0=95.4 \mathrm{~kJ}$

ii. $\quad \mathrm{N}_2 \mathrm{H}_{4(\mathrm{~g})}+\mathrm{H}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{NH}_{3(\mathrm{~g})}$;$$ \Delta_{\mathrm{t}} \mathrm{H}_2^0=-187.6 \mathrm{~kJ} $$

Which of the following is structural formula of mesityl oxide?

Which of the following compounds has lowest solubility in water?

Identify the major product formed in the following reaction.

Chlorobenzene $\xrightarrow[\text { Antilyctous } \mathrm{FeCl}_3]{\mathrm{Cl}_2}$ Product