ECAT Pre Engineering Chemistry Chapter 19 MCQ Test With Answer

The stability of acromatic compounds decreases with ------- in the no. of its resonance structure

• Decrease A
• Increase B
• Remain constant C
• Partially decreases D

Benzene has a -------- structure

• Pentagonal A
• Hexagonal B
• Heptagonal C
• Tetragonal D

The treatment of benzene with isobutene in the presence of sulphuric acid give

• isobutyl benzene A
• tert-Butyl benzene B
• n- Butyl benzene C
• no reaction D

C₁₈and onward hydrocarbons are normally

• Gases A
• Liquids B
• Solids C
• Plasma D

When an aqueous solution of potassium salt of monocarboxylic acid is subjected to electrolysis, corresponding alkane is formed. This reation is known as

• Cannizaro reaction A
• Sabatier-secderens reaction B
• Alkylation C
• Kolbe's reaction D

Synthesis rubber is made by polymerization :

• Chloroform A
• Acetylene B
• Divinyl acetylene C
• Butene D

• 4-methyl pentene A
• 2-methyle-1-butene B
• 2-methyl propane C
• None of the above D

The addition of unsymmetrical reagent to an unsymmetrical alkene is in accordance with the rule

• Hund's rule A
• Markowvikov's rule B
• Pauli's exclusion principle C
• Auf ban principle D

To differentiate isomers we use

• n- A
• iso- B
• neo C
• All of them D

The order of reactivity of halogens in aliphatic substitution reactions is

• Br2 > C12 > F2 A
• C12 > Br2 > F2 B
• C12 C12 > Br2 C
• F2 > Br2 > C12 D

How many molecules of chlorine adds in benzene in the presence of sunlight

• One A
• Two B
• Three C
• Four D

Acetylene is used in the manufacture of

• Rubber A
• Plastic B
• Ethyle alcohol C
• All of these D

Hydrocarbons are divided into aliphatic, alicyclic and aromatic which structure among the following show an alicyclic hydrocarbon

• 
  A
• 
  B
• 
  C
• 
  D

Amongst the following the compound that can be most readily sulphonated is

• Toluene A
• Benzene B
• Nitrobenzene C
• Chlorobenzene D

Hydrocarbon which is liquid at room temperature is

• Pentane A
• Butane B
• Propane C
• Ethane D

Free radical mechanism of halogenation of alkanes follow step:

• Initiation A
• Propagation B
• Termination C
• All of these D

Which of the following possesses the highest melting point?

• Chlorobenzene A
• 0-Dichlorobenzene B
• m-Dichlorobenzene C
• p-Dichlorobenzene D

A single benzene ring can have ______ ortho position maximally

• One A
• Two B
• Three C
• Four D

Nitroalkane are used in

• Fuel A
• Solvents B
• Organic synthesis C
• All of them D

The term aromatic was derives from

• Greek word A
• Latin B
• Russian C
• English D

In which one of the following compound rings are not fused together at ortho positions

• Phenanthrene A
• Naphthalene B
• Diphenyemethane C
• Anthracene D

• 2-bromonitrobenzene A
• 2-nitrobromobenzene B
• 1-bromonitrobenzene C
• 1-nitrobromobenzene D

Ethylene decolorizes cold dilute solution of KMnO₄. This test is known as

• Colouration test A
• Baeyer's test B
• Silver mirror test C
• Ring test D

Meta directing group decreased the ----------- of benzene ring

• Physical activity A
• Chemical reactivity B
• Density C
• None D

The three alternate single and double bonds in the benzene ring are called

• Conjugate bonds A
• Resonating bonds B
• Both A and B C
• None of above D

When n-hexane is heated in the presence of Pt at 500°C, it cyclists to give

• Benzene A
• Cyclohexene B
• Benzene C
• Toluene D

• 2, 3-dimethylbutane A
• 2, 3-methylbutane B
• 2-dimethylbutane C
• Dimethylbutane D

Benzene does not undergo

• Substitution reaction A
• Addition reaction B
• Oxidation reaction C
• Elimination reaction D

During the preparation of alkynes the active metals that react with tetra halo-alkanes are

• Zn A
• Mg B
• Both a and b C
• None D

Preparation of vegetable ghee involves:

• Halogenation A
• Hydrogenation B
• Hydroxylation C
• Dehydrogenation D