ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

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

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

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

The empirical formula of a compound is CH₂O. What may be the compound

• C₂H₅OH A
• C₆H₅OH B
• HCOOH C
• 
  D

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

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

The atomic mass is measured in atomic mass unit (a.m.u.) which is equal to

• 1.661 x 10^{-27- Kg} A
• 1.661 x 10^-24Kg B
• 1.661 x 10^{-27- g} C
• 1.661 x 10^-24mg D

When 0.1 g of magnesium is treated with an excess of hydrochloric acid, what volume of gas at room temperature and pressure will be produced

• 10 cm³ A
• 25 cm³ B
• 48 cm³ C
• 100 cm³ D

The quantitative relationship between the substances according to balanced equation describes

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

Metal tend to lose electrons, becoming:

• Metals

  A

• Positively charged

  B

• Negatively charged

  C

• (a)And (c)

  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

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

Macromolecules are

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

CO+ is an example of

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

C₆H₁₂O₆and C₁₂H₂₂O₁₁ are:

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

• Hetero atomic molecules

  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

Isotopes of an element differ in

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

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

• Positrons

  A

• Photons

  B

• Ions

  C

• Electrons

  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

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

• 8 g A
• 16 g B
• 32 g C
• 24 g 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

The number of isotopes of gold is

• 3 A
• 1 B
• 2 C
• 4 D

The atom of an element is

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

Al³⁺is a symbol for aluminium

• Atom A
• Ion B
• Cation C
• Anion 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 number of atoms present in molecule determines its:

• Molecularity A
• Atomicity B
• Basicity C
• Acidity 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

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