ECAT Pre Engineering Chemistry Chapter 1 MCQ Test With Answer

Isotopes differ in the

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

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

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

The atom of an element is

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

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

Which has greater number of moles

• 0.1 g sodium A
• 6.02 x 10²⁰atoms of magnesium B
• 20 cm³0.1mole per dm³of NaOH C
• 12.2 dm³of nitrogen at standard
  [A_rNa = 23, Mg = 24, O = 16]
  D

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

Al³⁺is a symbol for aluminium

• Atom A
• Ion B
• Cation C
• Anion 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

The pressure of vapours when sent to the ionization chamber in mass spectrometer is

• 10^-5to 10^-6torr A
• 10^-6to 10^-7torr B
• 10^-7to 10^-8torr C
• 10^-3to 10^-4torr 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

The number of isotopes of gold is

• 3 A
• 1 B
• 2 C
• 4 D

Atoms can be evident by use of electron microscope, field ionization microscope and:

• x-rays A
• Video camera
  
  
  B
• Telescope C
• Compound microscope D

One mole of SO₂contains

• 6.02 x 10²³atoms of oxygen A
• 18.1 x 10²³, molecules of SO₂ B
• 6.02 x 10²³ atoms of sulphur C
• 4 gram atoms of SO₂ 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

• 
  A
• 
  B
• 
  C
• 
  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

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

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

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

• C A
• H B
• N C
• O D

A species having positive or negative charge is called:

• Electron A
• Ion B
• Proton C
• Atom 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

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

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

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

The negatively charged particles are called

• Cation A
• Radical B
• Anion C
• Positron 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

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

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