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

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 in grams B
• Total number of atoms C
• Number of molecules 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

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

X-ray work has shown that the diameters of atom are of the order of

• 8 x 10^-10m A
• 2 x 10^-10m B
• 8 x 10^-8m C
• 2 x 10^-8 m D

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

• Positrons

  A

• Photons

  B

• Ions

  C

• Electrons

  D

If four moles of sulpur dioxide are oxidised to sulphur trioxide, how many moles of oxygen molecules are required

• 0.5 A
• 1.0 B
• 1.5 C
• 2.0 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

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

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

The number of moles of CO2which contain 8.0 g of oxygen

• 0.25 A
• 0.50 B
• 1.0 C
• 1.50 D

NH₃, HCL, H₂O, HL are:

• Diatomic molecules

  A

• Poly-atomic molecules

  B

• Mono-atomic molecules

  C

• Hetero atomic molecules

  D

An ion bearing positive charge is called:

• Cation A
• Positron B
• Anion C
• None of above D

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

• 32 g A
• 3.2 g B
• 5.6 g C
• 9.6 g D

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

Each molecule of haemoglobin is 68000 times heavier than one atom of

• C A
• H B
• N C
• O 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

A species having positive or negative charge is called:

• Electron A
• Ion B
• Proton C
• Atom 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

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 compound having empirical formula C₃H₃O and its molecular mass is 110.02. Its molecular formula is

• C₃H₃O A
• C₆H₆O₂ B
• C₉H₉O₃ C
• C₃H₆O₂ D

Which one of the following statements is not correct

• A molecule is the smallest particle of an element which can exist independently A
• He is a molecule of helium B
• S₈is a molecule of sulphur C
• O₃is a molecule of oxygen 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

CL₂, N₂ and O_{2 are:}

• Diatomic molecules

  A

• Hetero atomic molecules

  B

• Poly-atomic molecules

  C
• Mono-atomic molecules D

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

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

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

The number of subatomic particles in atoms sidcovered is more than:

• 110 A
• 100 B
• 125 C
• 90 D