ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

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

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

• Positrons

  A

• Photons

  B

• Ions

  C

• Electrons

  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

One mole of C₂H₅OH contains the number of H-atoms

• 6.02 x 10²³ A
• 3.61 x 10²⁴ B
• 1.81 x 10²⁴ C
• 6.02 x 10²⁴ D

Benzene is stable to:

• Oxidation A
• Nitration B
• KMnO₄ C
• SULPHONATION 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 amount of products obtained from the balanced chemical equation is regarded as

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

The relative abundance of Pb isotopes is 1.5% Pb²⁰⁴, 23.6% Pb²⁰⁶, 22.6% Pb²⁰⁷, 52.3% Pb²⁰⁸The relative atomic mass of Pb is

• 207.94 A
• 208.24 B
• 206.94 C
• 207.24 D

The isotopes of an element

• Possess same mass number A
• Possess same number of protons B
• Do not possess same chemical properties C
• May or may not possess same chemical properties D

C₆H₁₂O₆and C₁₂H₂₂O₁₁ are:

• Mono-atomic molecules A
• Diatomic molecules B
• Poly-atomic molecules C

• Hetero atomic 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

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

Hemoglobin is 68000 times heavier than:

• Oxygen atom A
• Nitrogen atom B
• Carbon atom C
• Hydrogen atom D

Which one of the following compounds does not have the empirical formula CH₂O?

• Ethanoic acid, CH₃CO₂H A
• Ethanol, CH₃CH₂OH B
• Glucose, C₆H₁₂O₆ C
• Methanal, HCHO 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 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

First atomic theory was put forward by an English school teacher:

• Maxewell A
• Newton B
• Sanger C
• John Dalton D

Covalent compound s mostly exist in the form of:

• Protons

  A

• Atoms

  B
• Neutrons C

• Molecules

  D

One mole of ethanol and one mole of ethane have an equal

• Mass A
• Number of atoms B
• Number of electrons C
• Number of molecules D

Mass spectrometer measures the

• Exact mass of an element A
• Average mass of an element B
• The number of elements present in a molecule C
• m/e value of a positive ion D

Isotopes differ in the

• Number of neutrons A
• Number of protons B
• Number of electrons C
• Number of atoms 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

Al³⁺is a symbol for aluminium

• Atom A
• Ion B
• Cation C
• Anion 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 empirical formula of a compound is CH₂O. What may be the compound

• C₂H₅OH A
• C₆H₅OH B
• HCOOH C
• 
  D

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

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

• N₂O₄is limiting reactant A
• N₂H₄is the limiting reactant B
• Reactants are completely converted to the products C
• Reactions is reversible 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 mass of one mole of proton is

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