Consider the following relations for emf of an electrochemical cell
(i)   EMF of cell = (Oxidation potential of anode) $$-$$ (Reduction potential of cathode)
(ii)  EMF of cell = (Oxidation potential of anode) + (Reduction potential of cathode)
(iii) EMF of cell = (Reductional potential of anode) + (Reduction potential of cathode)
(iv) EMF of cell = (Oxidation potential of anode) $$-$$ (Oxidation potential of cathode)

Which of the above relations are correct?

The rate of the reaction, 2NO + Cl₂ $$ \to $$ 2NOCl is given by the rate equation rate = k[NO]²[Cl₂]. The value of the rate constant can be increased by

How many bridging oxygen atoms are present in P₄O₁₀?

Match List I (substances) with List II (processes) employed in the manufacture of the substances and select the correct option.

Column $${\rm I}$$ (Substances)			Column $${\rm I}$$$${\rm I}$$ (Processes)
(A)	Sulphuric acid		(i)	Haber's process
(B)	Steel		(ii)	Bessemer's process
(C)	Sodium hydroxide		(iii)	Leblanc process
(D)	Ammonia		(iv)	Contact process