ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

Formation of a cation is:

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

Covalent compound s mostly exist in the form of:

• Protons

  A

• Atoms

  B
• Neutrons C

• Molecules

  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

CO+ is an example of

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

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

• 99.2% A
• 99.5% B
• 90.5% C
• 96.2% 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

• 8 g A
• 16 g B
• 32 g C
• 24 g D

Benzene is stable to:

• Oxidation A
• Nitration B
• KMnO₄ C
• SULPHONATION 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

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

The number of isotopes of gold is

• 3 A
• 1 B
• 2 C
• 4 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

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 number of subatomic particles in atoms sidcovered is more than:

• 110 A
• 100 B
• 125 C
• 90 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

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

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

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

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

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

• 
  A
• 
  B
• 
  C
• 
  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

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

Objects of the size of an atom can be observed in

• An electron microscope A
• An x-ray spectrum B
• Atomic absorption spectrum C
• A visible spectrum D