Four statements about benzene molecule are given below. Of these which is the correct statement justify your answers.
i. Because of unsaturation benzene easily undergoes addition reaction.
ii, There are two types of C-C bonds in benzene molecule.
iii. There is a cyclic delocalisation of 'pi' electrons in benzene
iv. Di substitution of benzene group gives two isomeric substances.

Four statements about benzene molecule are given below of these which is not correct statement. Justify your answer.

Select the correct statement(s) given below: (I) Both - Cl group as well as - OCOCH_3 group deactivate benzene ring towards electrophilic aromatic substitution reactions.

Which one of the statements given below concerning properties of solutions, describes a colligative effect? a)Boiling point of pure water decreases by the addition of ethanol b)Vapour pressure of pure water decreases by the addition of nitric acid c)Vapour pressure of pure benzene decreases by the addition of naphthalene d)Boiling point of pure benzene increases by the addition of toluene

Assertion : Borazole, known as inorganic benzene is more reactive than benzene Reason : In borazole, B-N bonds are polar whereas in benzene C-C are non polar (I) Both assertion and reason are correct and reason is the correct explanation of assertion. (II) Both assertion and reason are correct and reason is not the correct explanation of assertion. (III) Assertion is true and reason is false (IV) Assertion is false,reason is true

Which of the following statements are correct? Fuel cells are galvanic cells in which the chemical energy of fuel is directly converted into electrical energy. Type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst (platinum, silver, or metal oxide). The electrodes are placed in aqueous solution of NaOH. Oxygen nad hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(oplus) which is neutralized by overset(Θ)(OH) , ie., anodic reaction. H_(2) hArr 2H^(oplus) + 2e^(-) 2H^(oplus) + 2 overset(Θ)(OH) hArr 2H_(2)O H_(2) + 2 overset(Θ)(OH) hArr 2H_(2)O + 2e^(-) At cathode, O_(2) gets reduced to overset(Θ)(OH) i.e., O_(2) + 2H_(2)O + 4e^(-) hArr overset(Θ)(4)OH Hence, the net reaction is 2H_(2) + O_(2) hArr 2H_(2)O The overall reaction has Delta H= -285.6kJ mol^(-1) and Delta G= -237.4kJ mol^(-1) " at " 25^(@)C A fuel cell is I. A voltaic cell in which continuous supply of fuels are sent at anode to perform oxidation II. A voltaic cell in which fuels such as CH_(4), H_(2) and CO are used up at anode. III. One which involves the reaction of H_(2)- O_(2) fuel cell such as: Anode 2H_(2) + 4 overset(Θ)(OH) rarr 4H_(2)O(I) + 4e^(-) cathode : O+ 2H_(2)O(I) + 4e^(-) rarr 4 overset(Θ)(OH) IV. The efficiency of H_(2)-O_(2) fuel cell is 70 to 75%

When bromo benzene is monochlorinated, two Isomeric compounds A and B are obtained. Monobromination of A gives several isomeric products of molecular formula C_6 H_3 CI Br_2 , while monobromination of B yields only 2 isomers C and D . Compound C is identical with one of the compounds obtained from bromination of A , however D is totally different from any of the isomeric cómpounds obtained from the bromination of A , Give structures of A, B, C and D and also structures of four isomeric monobrominated products of A Support your answer with reasoning.

Carboxylic acid, although unreactive to alcohols, reacts in the presence of small amount of conc. H_(2)SO_(4) or with 2-3% of HCl? RCOOH+R'OH overset(H^(o+))hArr RCOOR'+H_(2)O Which of the following is correct about the above reaction? I. This reaction is called Fischer esterification reaction. II. The equilibrium is shifted to R.H.S. if H_(2)O is removed by azeotropic distillation with benzene. III. The reaction of RCOCl and R'OH to give ester(RCOOR') is irreversible and more feasible than esterification of RCOOH IV. If the above esterification of RCOOH is carried out in excess of R'OH, the equilibrium is shifted to R.H.S.