ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

He Ar and Ne are:

• Mono-atomic molecules A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C

• Diatomic molecules

  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

Macromolecules are

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

A molecule of haemoglobin is made up if nearly

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

In molecules kinetic and potential energies are:

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

Molecules of High molecular weight usually greater than 10,000 are called:

• Macro molecules A
• Mega molecules B
• Poly molecules C
• Gega molecules D

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

Covalent compound s mostly exist in the form of:

• Protons

  A

• Atoms

  B
• Neutrons C

• Molecules

  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

When nitrogen is 5.6 grams in NO₂. then number of moles of NO₂is

• 0.5 A
• 0.4 B
• 0.04 C
• 0.05 D

The branch of science dealing with structure, composition and changes in matter and laws and principles which govern these changes is called as

• chesmistry A
• Geology B
• Physics C
• Mechanics D

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

Which of the following statements is not true?

• Isotopes with even atomic masses are comparatively abundant A
• Isotopes with even atomic masses are comparatively abundant B
• Isotopes with even atomic masses and even atomic numbers are comparatively abundant C
• Isotopes with even atomic masses and odd atomic number are comparatively abundant D

CO+ is an example of

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

Benzene is stable to:

• Oxidation A
• Nitration B
• KMnO₄ C
• SULPHONATION D

CL₂, N₂ and O_{2 are:}

• Diatomic molecules

  A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C
• Mono-atomic molecules D

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

• Positrons

  A

• Photons

  B

• Ions

  C

• Electrons

  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

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

0.5 mole of CH4and 0.5 mole of SO2gases have equal

• Volume A
• Mass in grams B
• Total number of atoms C
• Number of molecules 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

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

The relative atomic mass of chlorine is 35.5. What is the mass of 2 mol of chlorine gas

• 142 g A
• 71 g B
• 35.5 g C
• 18.75 g D

• 8 g A
• 16 g B
• 32 g C
• 24 g D