ECAT Pre Engineering Chemistry Chapter 19 MCQ Test With Answer

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

The C-C bond angles in benzene ring are

• 119° A
• 120° B
• 121° C
• None D

Benzene is prepared from n-hexane in the presence of catalyst

• Cr₂O₃ A
• Al₂O₃ B
• SiO₂ C
• All above D

The presence of a double bond in a compound in the sign of:

• Saturation A
• Unsaturation B
• Subsitution C
• None D

Which decolourizes the colour of Br₃

• CH₄ A
• CH_3-CH_3-CH₃ B
• CH₂₌CH₂ C
• CH_3-CH₃ D

Physical properties of alkanes increase with increase of all physical constants except

• Boiling points A
• Melting points B
• Density C
• Solubility D

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

• One A
• Two B
• Three C
• Four D

The difference between amount of heat actually released and that of calculated is called

• Bonding energy A
• Activation energy B
• Resonance energy C
• Transition energy D

When sodium benzoate is treated with soda lime (NaOH) benzene is formed. What is the other product

• Na₂CO₃ A
• NaHCO₃ B
• Ca(OH)₂ C
• CaCO₃ D

The temp. used for the hydrogenation of alkenes using Ni is

• 2000°C A
• 400°C B
• 200-- 300°C C
• 1000°C D

Paraffins are also called

• Alkanes A
• Alkynes B
• Alkenes C
• None of these D

Which reaction sequence would be best to prepare 3-chloro-aniline from benzene?

• Chlorination, nitration, reducing A
• Nitration, chlorination, reducition B
• Nitration, reduction,chlorination C
• Nitration, reduction, acylation, chlorination, hydrolysis D

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

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

Zn + HCI are used in

• Clemenson reduction A
• Wof kishner reduction B
• Kolb's electrolysis C
• Wutruz reaction D

All are ortho & Para directing except

• X A
• OH B
• NR₃ C
• NH₂ D

An organic compound, on treatment with Br2 in CC14 gives bromoderivative of an alkene. The compound will be

• CH3 - CH = Ch2 A
• CH3CH = CHCH3 B
• HC = CH C
• H2C = CH2 D

Alkanes have functional group :

• ----X A
• --OH B
• ----COH C
• No functional group D

Acetylene gives

• White ppt. with ammonical AgNO3 and red ppt. with ammonical Cu(NO3)2 A
• White ppt. with ammonical AgNO3 and red ppt. with ammonical Cu2C12 B
• White ppt. with both C
• Red ppt. with both D

Hybridization of each carbon atom in benzene ring is

• sp hybridized A
• sp²hybridized B
• sp³ C
• dsp² D

Which gas is used for welding purposes

• Butane A
• Nitrogen B
• Methane C
• Acetylene D

Incomplete oxidation of alkanes yields

• CO₂& carbon black A
• CO₂+ heat B
• CO and carbon black C
• CO + heat D

Catalytic oxidation of alkanes is used for the preparation of

• Adehydes A
• Ketones B
• Fatty acid C
• Carbonyylic acids D

Sp³hybird orbitals are oriented at an angle of

• 107.5° A
• 108.5° B
• 109.5° C
• 103.5° D

The next homologue of C₁₀H₂₂will be

• C₉H₂₀ A
• C₁₂H₂₆ B
• C₁₁H₂₄ C
• C₁₃H₂₈ D

All C - H bond lengths of benzene ring is

• 1.07A° A
• 1.09A° B
• 1.08A° C
• None D

Introduction of a second methyl group in methylbenzene will give how many isomeric dimethyllenzenes

• 2 A
• 1 B
• 3 C
• 4 D

When alkyl is treated with chlorine in the presence of sunlight

• 1,3 dichloroproduct is formed A
• 1,4 dichloro product is formed B
• 1,3,5 trichloro product is formed C
• Only alkyl group is substituted D

Hydrocarbon which is liquid at room temperature is

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

During nitration of benzene, the active nitrating agent is

• NO3 A
• NO2+ B
• NO2- C
• HNO3 D

Which of the following is not an ortho-para directing group

• 
  A
• 
  B
• 
  C
• 
  D