ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

CO+ is an example of

• Stable molecule A
• Anionic molecule ion B
• Cationic molecular ion C
• Free radical D

How is the secondary structure of protein stabilized

• Through hydrogen bonding A
• Through ionic bonding B
• Through van der wall forces C
• Through covalent bonding D

What will be the weight of deposited silver on passing 965 coulombs of electricity in solution of AgNO₃?

• 1.08 g A
• 2.16 g B
• 0.54 g C
• 0.27 g D

The net heat in a chemical reaction is same, whether it is brought about in two or more different ways in one or several steps. It is known as

• Henry's law A
• Joule's princile B
• Hess's law C
• law of conservation of energy D

The electronic configuration of an atom/ion can be defined by the following

• Aufbau principle A
• Pauli's exclusion principle B
• Hund's Rule C
• All the above D

During dehydration of alcohols to alkenes by heating with conc. H₂SO₄, the initial step is

• Formation of an ester A
• Protonation of alcohol molecule B
• Formation of carbocation C
• Elimination of water D

Electronic configuration of Cu⁺²is

• 4S², 3d⁹ A
• 4s^-1, 3d¹⁰ B
• 4S⁰, 3d⁹ C
• None of these D

Catenation is a process in which carbon shows the properties of making

• Multiple bonds A
• Hybridization B
• Long chains or rings of carbon atom C
• Showing isomerism D

Amides on treatment with Br₂and KOH are converted into amines, the reaction is known as

• Hoffmann's bromamide reaction A
• Hoffmann's methylation B
• Gabriel phthalimide reaction C
• H.V.Z reaction D

In a group IIA from top to bottom as the atomic number increases, there is regular decreases in

• Ionic size A
• Atomic size B
• Ionization potential C
• None of these D

The solution of which acid is use for seasoning of food?

• Formic acid A
• Acetic acid B
• Benzoin acid C
• Butanoic acid D

To calculate volume of the solvent, we need to know, the :

• Density of solute A
• Normality of solute B
• Mass of solute C
• Molarity of solute D

Calcium carbide reacts with water to produce

• Acetylene A
• Methane B
• Ethylene C
• Ethane D

The bond order in No is 2.5 while that in NO⁺is 3.Which of the following statements is true for these two species?

• Bond length in NO⁺is greater than in NO A
• Bond length in unpredictable B
• Bond length in NO⁺is equal to that in NO C
• Bond length in NO is greater than in NO⁺ D

Which substances haveΔH =ΔE

• Solids A
• Liquids B
• Gases C
• Liquids and solids D

• Homogeneous A
• Heterogeneous B
• Isogeneous C
• None D

Swage water is purified by

• Microorganisms A
• Light B
• Fishes C
• Aquatic plants D

Dobereiner gave his law in the year:

• 1829 A
• 1864 B
• 1871 C
• 1931 D

Which one is the most toxic?

• Carbon A
• CO B
• CO₂ C
• SO₂ D

Which of the following statements is no correct regarding bonding molecular orbitals?

• Bonding molecular orbitals possess ls energy than atomic orbitals from which they are formed. A
• Bonding molecular orbitals have low electron density between the two nuclei. B
• Every electron in bonding molecular orbitals contributes to the attraction b.w atoms. C
• Bonding molecular orbitals are formed when the electron waves undergo constructive interference. D

Solvent extraction is an unstable, Process and it is called by:

• The amount of solute A
• Distribution law B
• The amount of solvent used C
• Law of mass action D

Which of the following molecules have sp³hybridized carbon

• CH₄ A
• C₂H₄ B
• C₂H₂ C
• CO₂ D

The oxides of beryllium are

• acidic A
• basic B
• amphoteric C
• none of these D

The most commonly and widely used nitrogen fertilizer in Pakistan is

• Urea A
• Ammonium nitrate B
• Ammonium sulphate C
• Ammonium chloride D

denaturing of alcohol is done by adding methanol in ethanol:

• 10% A
• 20% B
• 30% C
• 40% D

• Fe is reduced A
• Fe is oxidized B
• Cl₂is oxidized C
• None of these D

Bond angle in benzene is :

• 109..5^o A
• 180^o B
• 120^o C
• 107.2^o D

Which element among the following belongs to Group IV-A of the periodic table?

• Barium A
• Iodine B
• Lead C
• Oxygen D

Which of the following does give violet colour with neutral ferric chloride?

• Acetic acid A
• Salicaylic acid B
• Formine acid C
• Benzoic acid D

Which halogen occurs naturally in a positive oxidation state?

• Fluorine A
• Chlorine B
• Bromine C
• Iodine D