ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

An ion bearing positive charge is called:

• Cation A
• Positron B
• Anion C
• None of above D

A beaker contains 9 grams of water. The number of H-atoms is

• 6.02 x 1023 A
• 3.01 x 1023 B
• 6.02 x 1024 C
• 3.01 x 1024 D

The relative abundance of the ions with a definite m/e value is measured by

• High pressure of vapours A
• Strength of electric current measured B
• Quantity of fast moving electrons C
• Electron gas D

The branch of science dealing with structure, composition and changes in matter and laws and principles which govern these changes is called as

• chesmistry A
• Geology B
• Physics C
• Mechanics D

The diameter of atoms is of the order:

• 2* 10^-5m A

• 2* 10^-10 m

  B
• 2* 10^-2m C
• 2* 10^-3m D

Covalent compound s mostly exist in the form of:

• Protons

  A

• Atoms

  B
• Neutrons C

• Molecules

  D

The atom of an element is

• The smallest particle A
• The fundamental particle B
• The independent particle C
• The charged particle D

In molecules kinetic and potential energies are:

• Definite A
• Moderate B
• Indefinite C
• None of above D

Atoms and molecules can either gain or lose electrons, forming charge particles called:

• Positrons

  A

• Photons

  B

• Ions

  C

• Electrons

  D

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

The phenomenon of isotropy was first discovered by

• Soddy A
• Rutherford B
• Bohr C
• Dalton D

Isotopes of an element differ in

• Number of protons A
• Number of electrons B
• Number of neutrons C
• Number of electrons and protons D

Two different hydrocarbon each contain the same percentage by mass of hydrogen. It follows that they have the same

• Empirical formula A
• Number of atoms in a molecules B
• Number of isomers C
• Relative molecular mass D

The wave length of visible light is 500 nm. In S.I. unit this value is

• 5 x 10^-8m A
• 5 x 10^-9m B
• 500 x 10^-7m C
• 500 x 10^-9m D

One of the following statements is incorrect

• Actual yeild is always less than the theoretical yield A
• The formula of a compound is not definite B
• Law of conservation of mass is applied in stoictiometry C
• Boyles law is applied in stoichiometry D

Isotopes differ in

• properties which depend upon mass A
• arrangement of electrons in orbitals B
• chemical properties C
• the extent to which they may be affected in electric fields D

When an electron is added to a uni positive ion we get:

• Cation A
• Molecule B
• Neutral atom C
• Anion D

What is the maximum mass of aluminium which can be obtained from 240g of aluminium oxide Al₂O₃?

• 26 g A
• 127 g B
• 51 g C
• 108 g D

What is the volume in cm³of 3.01 x 10²³molecules of O₂gas at S.T.P

• 1000 cm³ A
• 11000 cm³ B
• 1120 cm³ C
• 11200 cm³ D

The number of moles of CO2which contain 8.0 g of oxygen

• 0.25 A
• 0.50 B
• 1.0 C
• 1.50 D

A compound X contains 50% sulphur and 50% oxygen by mass. What is the empirical formula of compound X?

• SO A
• SO₂ B
• SO₃ C
• SO₄ D

Which of the following statement is correct for a chemical reaction to occur molecules of substances must

• Collide with each other A
• Collide with energy more than activation energy B
• Collide with energy less than activation energy C
• Collide with high frequency D

A limiting reactant is the one which

• Is taken in lesser quantity in grams as compared to other reactants A
• Is taken in lesser quantity in volume as compared to other reactants B
• Gives the maximum amount of the product which is required C
• Gives the minimum amount of the product under consideration D

The relative atomic mass of chlorine is 35.5. What is the mass of 2 mol of chlorine gas

• 142 g A
• 71 g B
• 35.5 g C
• 18.75 g D

A ring contains 3 gram diamond. The number of C-atoms which a ring contains is

• 3.01 x 10²³ A
• 1.5 x 10²³ B
• 6.02 x 10²⁴ C
• 3.01 x 10²⁴ D

The mass of Al₂S₃formed when 20 grams Al reacts completely with S is

• 60 g A
• 50 g B
• 50.55 g C
• 55.55 g D

A compound contains one atom of oxygen and % of O 34.78, then molecular mass of compound is

• 46 A
• 78 B
• 110 C
• 180 D

3.01 x 10²²Ag⁺ions is present in

• 85 grams AgNO₃ A
• 0.85 g AgNO₃ B
• 8.5 g AgNO₃ C
• 18.5 g AgNO₃ D

The mass of one mole of proton is

• 1.008 g A
• 0.184 g B
• 1.673 g C
• 1.008 mg D

The pressure of vapours when sent to the ionization chamber in mass spectrometer is

• 10^-5to 10^-6torr A
• 10^-6to 10^-7torr B
• 10^-7to 10^-8torr C
• 10^-3to 10^-4torr D