ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

The unit of rate constant is the same as that of the rate of reaction in :

• First order reaction. A
• Second order reaction. B
• Zero order reaction. C
• Third order reaction. D

If pH of buffer of 1 mole dm^-3of HCOOH + 0.1 mole dm^-3HCOONa having pKa = 3.78 is

• 1.78 A
• 2.78 B
• 3.78 C
• 4.78 D

A catalyst is a substance which increase the rate of a chemical reaction, but remains unchanged at the end of reaction, nut remains unchanged at the end of reaction, because

• It increases the temperature A
• It increase the surface area B
• It increases the rate constant C
• It decrease the energy energy of activation D

How many g of dibasic acid (mol. wt. 200) should be present in 100 ml of the aqueous solution to give 0.1 Normality?

• 1 g A
• 2 g B
• 10 g C
• 20 g D

The M.P. of carboxylic acids containing even number of carbon atoms is ______ than the next

• Higher A
• Low B
• Equal C
• None D

• Q and R Q and R A
• R only Q and R B
• Q and R R only C
• Q only R only D

Which element is deposited at the cathode during the electrolysis of brine in Nelson's cell?

• H₂ A
• Na B
• Cl₂ C
• O₂ D

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

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

Ozone layer of stratosphere requires protection from indiscriminate use of

• Fungicides, insecticides, bactericides and medicines A
• Aerosols and high flying jets B
• Atomic explosions and industrial wastes C
• Baloons and turbo-prop aeroplanes D

How many moles of oxygen, O₂are needed for the complete combustion of two moles of butane C₄H₁₀?

• 2 A
• 8 B
• 10 C
• 13 D

Electronegativity values of the elements F, CI and Br vary

• F > CI > Br A
• Br > CI > F B
• Cl > Br > F C
• CI > F > Br D

The pH of 10^-3mole dm^-3of an aqueous solution of H₂SO₄is

• 3.0 A
• 2.7 B
• 2.0 C
• 1.5 D

Law of mass action was given by :

• Guldberg and Waage. A
• Berkeley and Hartly. B
• Ramsay and Reyleigh. C
• Berthelot. D

NaH is

• Ionic hydride A
• Complex hydride B
• Covalent hydride C
• Interstitial hydride D

The conductivity of strong electrolyte

• Increases on dilution slightly A
• Does not change on dilution B
• Decreases on dilution C
• Depends on density of electrolyte it self D

• There is no change in temperature A
• No change in volume B
• Heat is absorbed C
• Heat is released D

In t-butyl alcohol, the tertiary carbon is bonded to:

• Two hydrogen atom A
• Three hydrogen atoms B
• One hydrogen atoms C
• No hydrogen atoms D

Which of the following is not an element?

• Graphite A
• Diamond B
• 22-Carat gold C
• Rhombic sulphur D

Acetal is produced by reacting alcohol in the presence of dry HCl with

• Acetaldehyde A
• Ketone B
• Ether C
• Carboxylic acid D

Which of the following is a member of -block

• Zn A
• Al B
• B C
• Br D

Ratio of carbon to hydrogen in aromatic compounds is:

• Low than alkanes A
• High than alkanes B
• Low than alkanes not high than alkanes C
• High than alkanes D

Which of the following compounds contains the highest percentage by mass of nitrogen?

• Ammonia, NH₃ A
• Ammonium carbamate, NH₂CO₂NH₄ B
• Ammonium carbonate, (NH₄)₂CO₃ C
• Hydrazine, N₂H₄ D

The cell which generates electricity as a result of spontaneous oxidation-reduction reaction is called

• Electrolytic cell A
• Nelson's cell B
• Galvanic cell C
• Down's cell D

In an electrolytic cell, the electrons flow from :

• Cathode to anode or opposite A
• Cathode to anode B
• Anode to cathode C
• Random flow D

An ionic compound A+B is most likely to be formed when

• The ionization energy of A is high and electron affinity of B is low. A
• The ionization energy of A is low and electron affinity of B is high. B
• Both ionization energy of A and electron affinity of B are high. C
• Both ionization energy of A and electron affinity of B are low. D

Ethanol is prepared in Pakistan form fermentation of:

• Starch A
• Sugar B
• Glucose C
• Molasses D

Which element forms an iron with charge 3+?

• Berylium A
• Aluminium B
• Carbon C
• Silicon D

Laughing gas is chemically

• NO A
• N_2O B
• NO₂ C
• N₂O₄ D

• The heat released is enthalpy of neutralization A
• The heat released is enthalpy of atomization B
• The heat released is enthalpy of sublimation C
• The heat released is enthalpy of formation D

Which of the following is a natural polymer?

• Terylene A
• Polysaccharide B
• Nylon C
• Polyethene D