ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

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

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

CO+ is an example of

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

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

The amount of products obtained from the balanced chemical equation is regarded as

• Theoretical yield A
• Actual yield B
• % yield C
• Experimental yield D

The percentage of H is the highest in

• CH₄ A
• NH₃ B
• H₂SO₄ C
• C₆H₁₂O₆ 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

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

Macromolecules are

• organic molecules A
• High molecular mass molecules B
• Natural compounds C
• Rarely occurring molecules D

In molecules kinetic and potential energies are:

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

Relative atomic mass of an element is the mass of the element relative to

• 1/12 mass of carbon-12 A
• 1/12 mass of carbon B
• 1 mass of hydrogen atom C
• 1/16 mass of oxygen D

The negatively charged particles are called

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

Which of the sub-atomic particles is not charged

• Electron A
• Proton B
• Neutron C
• All of them D

A compound contains 75% carbon and 25% hydrogen, by mass. What is the molecular formula of the compound/

• C₃H₈ A
• CH₄ B
• C₂H₄ C
• C₂H₆ D

• 
  A
• 
  B
• 
  C
• 
  D

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

• Carbon A
• Hydrogen B
• Nitrogen C
• Oxygen 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

Isotopes of an element differ in

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

• 32 g A
• 3.2 g B
• 5.6 g C
• 9.6 g D

He Ar and Ne are:

• Mono-atomic molecules A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C

• Diatomic molecules

  D

How many moles of hydrogen atoms does 3.2 g of methane, CH₄, contain?

• 0.02 A
• 0.2 B
• 0.4 C
• 0.8 D

A molecule of haemoglobin is made up if nearly

• 10,000 atoms A
• 50,000 atoms B
• 2500 atoms C
• 1500 atoms 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

CL₂, N₂ and O_{2 are:}

• Diatomic molecules

  A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C
• Mono-atomic molecules 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

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

Formation of a cation is:

• Exothermic process A
• Non-endothermic process B
• Endothermic process C
• None of above 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