Which of the following statements about photochemical smog is wrong? 

(i) It has a high concentration of oxidizing agents. 

(ii) It has a low concentration of oxidizing agents. 

(iii) It can be controlled by controlling the release of NO₂ , hydrocarbons, ozone etc. 

(iv) Plantation of some plants like Pinus helps in controlling photochemical smog.

How many of these compounds will undergo disproportionation on hydrolysis? CO?, NO?, Cl?, F?, ClO?, Cl?O?, N?O?, SO?, P?O??

40. Best reducing agent is:
(a) He              (b) Be           (c) Li            (d) Al

37. Which element is considered to have oxidation number of +3 in all its compounds?

(a) Be              (b) Li             (c) Al         (d) Sc

36. Oxidation number ofS in S₂O₈^-2 is

(a) -2           (b) -6           (c) +2          (d) +6

32. Assertion: Na⁺ ion has an oxidation number of +1, Mg²⁺ ion, +2, Fe³⁺ ion, +3, Cl^– ion, –1, O^2– ion, –2; and so on.

Reason: For ions composed of only one atom, the oxidation number is equal to the charge on the ion.