ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

• s A
• p B
• d C
• f D

Which of the following is not charged particle

• Proton A
• Electron B
• Neutron C
• Hydrogen nucleus D

The range of visible spectrum is

• 300 - 600 nm A
• 600 - 900 nm B
• 400 - 750 nm C
• 100 - 300 nm D

When the 6d orbital is completed the entering electron goes into

• 7f A
• 7 s B
• 7 p C
• 7 d D

In the ground state of an atom the electron is present

• In the nucleus A
• In the second shell B
• Nearest to the nucleus C
• Farthest from the nucleus D

Splitting of spectral lines of the hydrogen atom under the influence or magnetic field is called

• Stark effect A
• Zeeman effect B
• Compton effect C
• Photoelectric effect D

The total number of orbitals possible for the quantum number n is

• n A
• n² B
• 2n C
• 2n² D

The wave number of the light emitted by a certain source is 2 x 10⁶m^-1. The wavelength of this light will be

• 500 nm A
• 500 m B
• 200 nm C
• 5 x 10⁷m D

Positive particle in discharged tube is produced by ionization of gas molecules, which is caused by

• Gas molecules collide with anode A
• Gas molecules are at high temperature B
• Gas molecules produce X-rays C
• Cathode rays remove electrons from gas molecules D

The experimental evidences for the existence of atomic nucleus comes from:

• Line spectrum of hydrogen. A
• Magnetic bonding of cathode rays. B
• Millikan oil drop experiment. C
• Scattering of alpha particles by thin metal foil. D

The quantum number which describes the shape of the orbital is

• Principle quantum number A
• Spin quantum number B
• Azimathal quantum number C
• Magnetic quantum number D

Alpha rays consist of:

• Neutrons. A
• Helium nucleus. B
• Protons. C
• Hydrogen nucleus. D

Light emitted from a source has its wave length 500nm, then its wave number will be

• 2 x 10⁶m^-1 A
• 2 x 10⁷m^-1 B
• 5 x 10⁸ m^-1 C
• 5 x 10⁹m^-1 D

In the atomic emission spectrum the lines which appear bright, appear dark in absorption spectrum because

• The radiations emitted in emission spectrum are absorbed in absorption spectrum A
• Atomic emission spectrum is continuous B
• Atomic absorption spectrum is continuous C
• Distance between the lines increases D

The order of frequency of the following radiations unltraviolet, visible, infrared and microwave is

• Microwave > infrared > visible > ultraviolet A
• Visible > ultraviolet > microwave > infrared B
• Ultraviolet > visible > infrared > microwave C
• Infrared > microwave > ultraviolet > visible D

With the reference of w/m ratio of anode rays, the e/m ratio of cathode rays s:

• Greater. A
• same. B
• Smaller. C
• Not fixed. D

The energy of ionization of an atom is the energy difference between orbital

• 
  A
• 
  B
• 
  C
• 
  D

When the electron jumps form third, fourth, fifth orbits to the second orbit, the transitions are known as

• Paschen A
• Pfund B
• Balmer C
• Brackett D

The principle quantum number describes

• The distance form the nucleus A
• The shape of the orbital B
• The orientation of the orbital C
• The spin of the electron D

In Millikan method for determination of charge on electron the air in the chamber is ionized by

• Protons A
• Electric field B
• X-rays C
• a - particles D

Cathode rays emitted from cathode are

• Canal rays A
• Protons B
• Electrons C
• Positrons D

Proton was discovered by:

• Chadwick A
• J.J. Rhomson B
• Millikan. C
• Goldstein. D

An electron with n = 3 , l = 2 will be in the sub-shell

• 3p A
• 3d B
• 3f C
• 3s D

Charge on electron was discovered by:

• Millikan. A
• Crook. B
• Neil Bohr. C
• Rutherford. D

What is the packet of energy called?

• Electron A
• Photon B
• Positron C
• Proton D

The rules which describe the distribution of electron in atomic energy levels are Auf-ban principle, Pauli's exclusion principle. Hunds rule. The pauli exclusion principle refers to the

• Orientation of orbital in space A
• Fact that two electrons in the same orbital should have opposite spins B
• Energy of the orbital C
• Spin of the electron D

n + l value for 4f will

• 2 A
• 5 B
• 7 C
• 9 D

The charge of an electron is determined by

• J.J. Thomson A
• Crooks B
• Perrin C
• R.A.Millikan D

The ratio of the ionization energy of H and Be³⁺is

• 1 : 1 A
• 1 : 3 B
• 1 : 9 C
• 1 : 16 D

Which of the following has more unpaired d-electrons?

• Zn⁺ A
• Fe²⁺ B
• Ni³⁺ C
• Cu⁺ D