21.

Amongst the following, the compound that can most readily get sulphonated is :

• benzene

• toluene

• nitrobenzene

• chlorobenzene

The major product of the addition of water molecule to propyne in the presence of mercuric sulphate and dilute sulphuric acid is :

• ethanal

• 2-propanol

• propane

• propanone

Reaction of diborane with ammonia gives initially :

• B₂H₆ . NH₃

• borazole

• B₂H₆ . 3NH₃

• [BH2(NH3)2]⁺ [BH₄]^-

Use of chlorofluorocarbons is not encouraged because :

• they are harmful to the eyes of peoplethat use it

• they damage the refrigerators and air conditioners

• they eat away the ozone in the atmosphere

• they destroy the oxygen layer

Which ofthe following complexes exists as pair of enantiomers ?

• trans-[Co(en)₂Cl₂]⁺

• [Co(NH₃)₂Cl₂]⁺

• [Co{P(C₂H₅)₃}₂ClBr]

• [Cr(en)₃]³⁺

Alum is a water purifier, because it :

• coagulates the impurities

• softens hard water

• gives taste

• destroys the pathogenic bacteria

Gold is extracted by hydrometallurgical process, based on its property :

• of being electropositive

• of being less reactive

• to form complexes which are water soluble

• to form salts which are water soluble

The crystal with metal deficiency defect is :

• NaCl

• FeO

• KCl

• ZnO

How many moles of Pt may be deposited on the cathode when 0.80 F of electricity is passed through a 1.0 M solution of Pt⁴⁺ ?

• 1.0 mol

• 0.20 mol

• 0.40 mol

• 0.80 mol

1 g of a non-volatile, non-electrolyte solute of molar mass 250 g/mol was dissolved in 51.2 g of benzene. If the freezing point depression constant , k_f of benzene is 5.12 kg K mol^-1 , the freezing point of benzene is lowered by :

• 0.3 K

• 0.5 K

• 0.2 K

• 0.4 K