ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

• N₂O₄is limiting reactant A
• N₂H₄is the limiting reactant B
• Reactants are completely converted to the products C
• Reactions is reversible D

Which one of the following statements is not correct

• A molecule is the smallest particle of an element which can exist independently A
• He is a molecule of helium B
• S₈is a molecule of sulphur C
• O₃is a molecule of oxygen D

The number of subatomic particles in atoms sidcovered is more than:

• 110 A
• 100 B
• 125 C
• 90 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 mass of sulphur which combines with 24 grams oxygen to form SO₂

• 32 gram A
• 24 gram B
• 8 gram C
• 12 gram D

The percentage of which element in the organic compound is determined by the difference method

• Carbon A
• Hydrogen B
• Nitrogen C
• Oxygen 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

A balloon contains 0.02 gram of H₂gas, it contains H₂molecules

• 6.02 x 10²³ A
• 3.01 x 10²² B
• 6.02 x 10²¹ C
• 3.01 x 10²¹ D

A species having positive or negative charge is called:

• Electron A
• Ion B
• Proton C
• Atom 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 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

The negatively charged particles are called

• Cation A
• Radical B
• Anion C
• Positron D

The quantitative relationship between the substances according to balanced equation describes

• Reversible reactions A
• Stoichiometry B
• Limiting reacting C
• Percentage composition D

The percentage of H is the highest in

• CH₄ A
• NH₃ B
• H₂SO₄ C
• C₆H₁₂O₆ D

0.5 mole of CH₄and 0.5 mole of SO₂gases have equal

• Volume A
• Mass is gram B
• Total number of atoms C
• Number of molecules 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

Which statement about an atom is true ?

• The number of neutrons is not equal to number of electrons A
• Mass number is less than atomic number B
• All the elements have only one mass number C
• Mass number can be equal to atomic number D

Ascorbic acid contains 40.92% carbon, 4.58%, hydrogen and 54.4% oxygen. The empirical formula is

• C₃H₄O₃ A
• C₂H₄O₃ B
• C₃H₅O₄ C
• C₂H₃O₁ D

The volume occupied by 1.4 g of N₂ at S.T.P is

• 2.24 dm³ A
• 22.4 dm³ B
• 1.12 dm³ C
• 112 cm³ D

Matter is defined as any thing which occupies space and:

• Molecules A
• Mass B
• Compound C
• Molecules D

Determination of atomic masses and invention of system of writing symbols was made by:

• J. Berzelius A
• Democritus B
• Dalton 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

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

Atoms can be evident by use of electron microscope, field ionization microscope and:

• x-rays A
• Video camera
  
  
  B
• Telescope C
• Compound microscope D

Each molecule of haemoglobin is 68000 times heavier than one atom of

• C A
• H B
• N C
• O D

Which one of the following step is not involved in determination of empirical formula

• Determination % of each element A
• Determination of gram atom of each element B
• Determination of isotopes of each element C
• Determination of atomic ratio of element D

Metal tend to lose electrons, becoming:

• Metals

  A

• Positively charged

  B

• Negatively charged

  C

• (a)And (c)

  D

An ion bearing positive charge is called:

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

• 8 g A
• 16 g B
• 32 g C
• 24 g 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