ECAT Pre Engineering Chemistry Chapter 19 MCQ Test With Answer

Benzene is obtained from benzene sulphonic acid by treating with

• HCl A
• NaOH B
• H₂O C
• NaHCO₃ 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

Which is liquid among the following alkenes?

• Ethane A
• Propene B
• Butene C
• Pentene D

Which one of the following is (m-xylene)

• 1,2 dimethyl benzene A
• 1,3 dimethyl benzene B
• 1,5 dimethyl benzene C
• 1,4 dimethyl benzene D

The four bonds of carbon in methane are directed towards the corners of

• Cube A
• Pentagon B
• Hexagon C
• Tetrahedron D

Incomplete oxidation of alkanes yields

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

Ethylene combines with water in the presence of H₂SO₄+ HgSO₄and forms

• Ethyle chloride A
• Ethyle alcohol B
• Carboxylic acid C
• None of these D

The empirical formula of benzene is determined by

• IR spectra A
• U.V B
• Elemental analysis C
• NMR spectra D

Alkenes normally have ______ geometry

• Tetrachedral A
• Linear B
• Planer C
• None D

Odour of alkene is:

• Fruity A
• Odourless B
• Zarlic like C
• Irritating D

Cyclohexane can be converted not benzene in the presence of

• Pt at 100°C A
• Pt at 250°C B
• Pd at room temperature C
• Pt at room temperature D

Hybridization of each carbon atom in benzene ring is

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

Alkyne is :

• CH_3-CH₃ A
• CH₄ B
• CH₂₌CH₂ C
• C₂H₂ D

Aromatic hydrocarbons are the derivatives of

• Normal series of paraffins A
• Alkene B
• Benzene C
• Cyclohexane D

Mustard gas is a :

• Gas A
• Liquid B
• Solid C
• High boiling point D

When acetylene is passed through a copper tube at 300°C, it polymerizes to

• Polyacetylene A
• polyethylene B
• Benzene C
• None of these D

The hydrocarbon used for polymerization is

• Alkanes A
• Alkenes B
• Alkynes C
• All of above D

Sulphuric acid generates nitronium ion by reacting with

• Nitric acid A
• Nitrogen gas B
• Nitrous acid C
• Potassium nitrate D

Acetylene when treated with 10% H₂SO₄in the presence of HgSO₄adds one molecule of water to form

• Aldehydes A
• Esters B
• Alcohols C
• Acids D

Zn + HCI are used in

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

In Friedal-Craft's alkylation besides AlCl3 the other reactants are

• C6H6 + NH3 A
• C6H6 + NH4 B
• C6H6 + CH3Cl C
• C6H6 + CH3COCl D

The compound prepared by a substitution reaction of benzene is

• Acetophenone A
• Glyoxal B
• Cyclohexame C
• Hexabromo cyclohexane D

C₁₈and onward hydrocarbons are normally

• Gases A
• Liquids B
• Solids C
• Plasma 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

CnH_2nis the general formula of

• Alkanes A
• Alkanes B
• alkynes C
• None of above D

A salt producing hydrocarbon among these compounds is

• Ehyne A
• Ethene B
• Methane C
• Ethane D

The Total coal resources of Pakistan are estimated to be

• 184 billion A
• 184 million tones B
• 1.84 billion tounes C
• 1.84 million tonnes D

Benzene does not undergo polymerization and it is also resistant to

• Reduction A
• Oxidation B
• Alkylation C
• Ozonolysis 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

• Pent -1-ene-3-yne A
• 2-pentyne-4-ene B
• 1-pentene-3-yne C
• Pent-2-yen-4-ene D