Formation of photochemical smog involves the following reaction in which $$\mathrm{A}, \mathrm{B}$$ and $$\mathrm{C}$$ are respectively.

$$ \begin{aligned} & \text { i. } \mathrm{NO}_{2} \stackrel{\mathrm{h} v}{\longrightarrow} \mathrm{A}+\mathrm{B} \\ & \text { ii. } \mathrm{B}+\mathrm{O}_{2} \rightarrow \mathrm{C} \\ & \text { iii. } \mathrm{A}+\mathrm{C} \rightarrow \mathrm{NO}_{2}+\mathrm{O}_{2} \end{aligned} $$

Choose the correct answer from the options given below :

Which of the following is correct order of ligand field strength?

Which of the following compounds would give the following set of qualitative analysis ?

(i) Fehling's Test : Positive

(ii) Na fusion extract upon treatment with sodium nitroprusside gives a blood red colour but not prussian blue.

In the extraction of copper, its sulphide ore is heated in a reverberatory furnace after mixing with silica to: