ECAT Pre Engineering MCQ Test With Answer for Chemistry Full Book

During the formation of a chemical bond the potential energy of the system

• Decreases A
• Increases B
• Does not change C
• None of these D

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

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

Carbon monoxide, emitted by automobiles, prevents transport of oxygen in body due

• Combining with oxygen to form carbon dioxide A
• Destruction of hemoglobin B
• Preventing reaction between oxygen and hemoglobin C
• Forming stable compound with hemoglobin D

The radius of first orbit of hydrogen atom

• 0.329 A° A
• 0.429 A° B
• 0.529 A° C
• 0.229 A° D

H₂S is a gas while H₂O is a liquid at room temperature. It is due to:

• Less inter-molecular forces in water. A
• Covalent bonding H-O in water molecule. B
• Hydrogen bonding in water molecules C
• Ionic character in water molecules D

• 99.2% A
• 99.5% B
• 90.5% C
• 96.2% D

The acid used in lead storage cells is

• Phosphoric acid A
• Nitric acid B
• Sulphuric acid C
• Hydrochloric acid D

The change in heat energy at constant temperature is called

• Enthalpy change A
• Heat of vaporisation B
• Bond energy C
• Internal energy change D

Francium is an element at the bottom of Group I in the Periodic Table. Which one of the following predication is likely to be correct?

• It will react with water to liberate oxygen A
• Its hydroxide will be a strong alkali in water B
• Its carbonate will decompose on heating to give carbon dioxide C
• Its nitrate on heating will give nitrogen dioxide and oxygen D

What causes nitrogen to be chemically inert?

• Multiple bond formation in the molecule A
• Absence of bond distance B
• Short internuclear distance C
• High bond energy D

General formula of aliphatic carboxylic acids:

• R---OH A
• R----COH B
• R----CO---R C
• RCOOH D

Maximum variable oxidation state is of:

• Mn⁺² A
• Fe⁺³ B
• Cr⁺¹ C
• a and b D

Which of these polymers is an addition polymer?

• Nylon-6,6 A
• Polystyrene B
• Terylene C
• Epoxy resin D

An organic compound has the following properties ; It gives a positive tri-iodomethane test; it gives a yellow ppt, with 2, 4-DNP regent; it does not react with Tollen's reagent . Which compound would give these results

• CH₃CHO A
• CH₃CH₂OH B
• CH₃CH₂COCH₃ C
• CH₃CH₂CH₂CHO D

The conversion of n-hexane into benzene by heating in the presence of Cr₂O_{3 is called:}

• Isomerization A
• Aromatization B
• Dealkylation C
• Rearrangment D

Acetamide and NaOBr/OH^-produce

• Ethanamine A
• Methanamide B
• CH₃CN C
• NH₃ D

CO+ is an example of

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

SO₂and NO₂produce pollution by increasing

• Alkalinity A
• Acidity B
• Neutrality C
• Buffer action D

The hydration energy is the heat evolved when one mole of gaseous ion is dissolved in water. The hydration energy of an ion

• Increases with increase of charge to mass ratio A
• Decreases with increase of charge to mass ratio B
• Depends on sign of charge +ve or -ve C
• Depends upon the solvent D

The boiling point of an a zeotropic mixture of water and ethye alcohol is less than that of water and alcohol. The mixture shows

• That solution is highly saturated A
• No deviation from Raoult's law B
• Positive deviation from Raoult's law C
• Negative deviation from Raoult's law D

Smell of halogen is

• Fruity A
• Sweet B
• Irritating C
• Rotten egg D

• Step 1 Step 2
  HCI HCN
  A
• HcN,NaCH H₂SO₄ B
• H₂SO₄ K₂Cr₂O₇/H₂SO₄ C
• KCN HCI D

The % of CO₂is the atmosphere is

• 3.0% A
• 0.03% B
• 0.3% C
• 0.5% D

The simplest separating unit of a polymer is called:

• Monomer A
• Dimer B
• Trimmer C
• Macromer D

Increasing skin cancer and high mutation rate are due to

• Acid rain A
• Ozone depletion B
• CO pollution C
• CO₂Pollution D

At room temperature formaldehyde is

• Gas A
• Liquid B
• Solid C
• None of the above D

Planar geometry of molecules is due to

• sp³hybridization A
• sp²hybridization B
• sp hybridization C
• P - p overlap D

If the value of azimuthal quantum number is 3, then values of m the magnetic quantum no. will be

• 0, 1, 2, 3 A
• +3, +2, +1, -1, -2, -3 B
• 0, -1, -2 ,-3 C
• -3, 0, +3 D

The most acidic of the following compounds is

• P₂O₃ A
• Sb₂O₃ B
• B₂O₃ C
• As₂O₃ D

Theα-carbon of 19 out of 20α-amino acids found in protein is chiral or asymmetric. Hence they are optically active. Only one of the 20α-amino acids is not optically active which one is the

• Proline A
• Glycine B
• Hitidine C
• Alanine D