ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

Pauli's principle is applicable to

• Degenerate orbits A
• Two electrons in the same orbital B
• One electron C
• None D

The radius of second Bohr's orbit is

• 0.053 nm A
• 0.053/4 nm B
• 0.053 x 4 nm C
• 0.053 x 20 nm D

If the value of principal quantum number is 3. the total possible values for magnetic quantum number will be

• 1 A
• 4 B
• 9 C
• 12 D

The value of Plank's constant 'h' is

• 6.625 x 10^-34 A
• 6.625 x 10^-34J sec B
• 6.625 x 10^-34KJ C
• 6.625 x 10^-34K Cal D

The de-Brogile wavelength of a particle with mass 1g and velocity 100 m/s is

• 6.63 x 10^-33m A
• 6.63 x 10^-34m B
• 6.63 x 10^-35m C
• 6.65 x 10^-35m D

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

• 
  A
• 
  B
• 
  C
• 
  D

The maximum number of electrons in a subshell for which l = 3 is

• 14 A
• 10 B
• 8 C
• 4 D

The spectrum of He is expected to be similar to that of

• H A
• Na B
• He⁺ C
• Li⁺ D

The number of electrons in the M shell of the element with atomic number 24 is

• 24 A
• 12 B
• 13 C
• 8 D

An electron has principal quantum number 3. The number of its 1 subshell and 2 orbitals would be respectively

• 3 and 5 A
• 3 and 7 B
• 3 and 9 C
• 2 and 5 D

The four quantum numbers of the valency electron of potassium are

• 4,1,1,1/2 A
• 4,0,0,1/2 B
• 4,1,0,1/2 C
• 4,4,0,1/2 D

n + l value for 4f will

• 2 A
• 5 B
• 7 C
• 9 D

The nature of the positive rays depend on

• The nature of the electrode A
• The nature of the discharge tube B
• The nature of the residual gas C
• All of the above D

Heaviest particle is

• Meson A
• Neutron B
• Proton C
• Electron D

Orbitals having same energy are called

• Hybrid orbitals A
• Valence orbitals B
• Degenerate orbitals C
• D-orbitals D

Four d-orbitals contain four lobes while fifth contains only two lobes the orbital is

• dxy A
• dxz B
• dz² C
• dx²- y² D

Cathode rays emitted from cathode are

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

The correct set of quantum numbers (n,l and m) respectively of the unpaired electron of chlorine atom is

• 2,1,0 A
• 2,1,1 B
• 3,1,1 C
• 3,2,1 D

Smallest charge of electricity that has been measured so far is

• Charge on a-rays A
• Charge on electron (1.602 x 10^-19C) B
• Charge on x-rays C
• Charge on gamma rays D

Azimuthal quantum number of last electron of ₁₁Na is

• 1 A
• 2 B
• 3 C
• 0 D

• s A
• p B
• d C
• f 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

Effective magnetic moment of Sc³⁺ion is

• 1.73 A
• 0 B
• 5.92 C
• 2.83 D

The orbitals having n + l = 5 are

• 2p, 3d,3s A
• 3p, 3d, 5s B
• 3s, 4p, 4d C
• 5s, 4p, 3d D

The number of spherical nodes in 3p orbitals are

• One A
• Three B
• Non C
• Two D

Rutherford's experiment led to the discovery of

• Nucleus A
• Electron B
• Proton C
• alpha particle D

• Neutrons are attracted by nucleus A
• Neutrons carry out nuclear reactions B
• Neutrons carry no charge C
• Neutrons are electromagnetic radiations D

Charge to mass ratio (e/m) of the electron is determined by

• R. A. Millikan A
• J. J. Thompson B
• G. J, Stoney C
• None of these 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

Electrons in degenerate orbitals are placed in separate orbitals with same spin according to

• Hund's rule A
• Pauli exclusion principle B
• Aufbau principle C
• Mosley's law D