ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

The quantitative relationship between the substances according to balanced equation describes

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

One mole of SO₂contains

• 6.02 x 10²³atoms of oxygen A
• 18.1 x 10²³, molecules of SO₂ B
• 6.02 x 10²³ atoms of sulphur C
• 4 gram atoms of SO₂ D

A molecule of haemoglobin is made up if nearly

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

• 0 dm³ A
• 3 dm³ B
• 2 dm³ C
• 3 dm³ D

1.12 dm³of N₂gas at S.T.P. has mass of N₂gas

• 2.8 g A
• 2.4 g B
• 1.4 g C
• 14 g D

• 300 cm³ A
• 200 cm³ B
• 150 cm³ C
• 100 cm³ 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

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 diameter of atoms is of the order:

• 2* 10^-5m A

• 2* 10^-10 m

  B
• 2* 10^-2m C
• 2* 10^-3m 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

The mass of one mole of proton is

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

Which of the sub-atomic particles is not charged

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

Smallest particle of an element which may or may not have independent existence is known as:

• A molecule A
• An ion B
• An atom C
• An electron D

Matter is defined as any thing which occupies space and:

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

Where energy is released during a reaction it is

• Exothermic reaction A
• Endothermic reaction B
• A free radical reaction C
• A bond breaking reaction D

• 84.84 % A
• 89.89% B
• 81.81% C
• 90.90% 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

The empirical formula of a liquid compound is known to be C₂H₄O. What other information is needed to work out its molecular formula?

• The percentage composition of the compound A
• The relative molecular mass of the compound B
• The density of the compound C
• The volume occupied by one mole of the compound D

Which statement about molecule is incorrect ?

• Molecules of a substance are similar A
• Hemoglobin is a homo atomic molecules B
• Oxygen molecule is a macro molecule C
• It exist independently D

Macromolecules are

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

Covalent compound s mostly exist in the form of:

• Protons

  A

• Atoms

  B
• Neutrons C

• Molecules

  D

The largest number of molecules are present in

• 3.6 g of H₂O A
• 4.8 g of C₂H₅OH B
• 2.8 g of CO C
• 5.4 g of N₂O₅ D

A limiting reactant is one which according to the stoichiometric equation

• Has excess mass A
• Has least mass B
• Has excess number of moles C
• Has least number of moles D

The value of R(General Gas Constant) is

• 8.3134 JK^-1mole^-1

  A

• 1.987 Cal K^-1Mole^-1

  B
• Both a and b C

• 1.987 JK^-1mole^-1

  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

CL₂, N₂ and O_{2 are:}

• Diatomic molecules

  A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C
• Mono-atomic molecules D

The phenomenon of isotropy was first discovered by

• Soddy A
• Rutherford B
• Bohr C
• Dalton 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