ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

Find the magnetic moment of a divalent ion in aqueous solution if its atomic number is 25

• 3.0 BM A
• 4.9 BM B
• 5.9 BM C
• 6.9 BM 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

In the ground state, an element has 13 electrons in its M shell. The element is

• Copper A
• Chromium B
• Nickel C
• Iron D

No cathode rays are produced in the discharged tube when gas is under ordinary pressure even if voltage of 5000 to 10000 is applies. This reason is

• Voltage is low A
• Discharge tube is not coloured B
• Gas does not conduct current under ordinary pressure C
• Temperature low D

Effective magnetic moment of Sc³⁺ion is

• 1.73 A
• 0 B
• 5.92 C
• 2.83 D

Quantum number values for 2p orbitals are

• n = 2, l = 1 A
• n = 1, l = 2 B
• n = 1, l = 0 C
• n = 2, l = 0 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

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

The electronic configuration of an atom/ion can be defined by the following

• Aufbau principle A
• Pauli's exclusion principle B
• Hund's Rule C
• All the above D

When electron jumps from n₂= 2,3,4,5,.... orbit to n₁= 1 orbit in the hydrogen atom, the radiations emitted give the spectral lines

• Lyman series A
• Blamer series B
• Paschen series C
• Brackett series D

Schrodinger wave equation describes electron completely because

• It describes a set of four quantum number A
• It describes the particle nature of electron B
• It measures wavelength of electron C
• It describes electron moving in specific orbit D

Photons of yellow colour are ______ energetic than violet colour

• More A
• Less B
• Equal C
• None D

For principle quantum number n=4, the total number of orbitals having l = 3 is

• 3 A
• 7 B
• 5 C
• 9 D

Alpha rays consist of:

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

Which have better penetrating power

• Alpha rays A
• Beta rays B
• Gamma rays C
• X-rays D

The symbol of the element whose atoms have the outer most electronic configuration 2s²2p³is

• N A
• Li B
• P C
• Na D

The radiations with wavelength shorter than violet light are called

• Ultraviolet A
• Infrared B
• Microwave C
• Radio frequency 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

When electrons revolve in stationary orbits

• There is no change in energy level A
• They vecome stationary B
• They are gaining kinetic energy C
• There is increase in energy D

Cathode rays drive a small paddle wheel placed in their path. This observation shows that

• Cathode rays travel in straight lines A
• Cathode rays are negatively charged B
• Cathode rays produce x-rays C
• Cathode rays are material particles having momentum D

The divisibility of atom was shown by

• Stoney A
• J.J. Thomson B
• Millikan C
• Rutherford D

For a 3P subshell the set of principle and azimuthal quantum number is

• n = 1 , l = 2 A
• n = 3, l = 0 B
• n = 3, l = 1 C
• n = 1, l = 3 D

Electrons arranged in orbitals according to the increasing order of their n + l values, this rule is named as

• Hund's rule A
• Heisenberg's principle B
• Paulit exclusion principle C
• Auf bau principle D

Heaviest particle is

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

The mass of the neutron is of the order of

• 10^-23 kg A
• 10^-24kg B
• 10^-26kg C
• 10^-27kg D

• s A
• p B
• d C
• f D

Sodium chloride imparts a yellow colour to the Bunsen flame. This can be interpreted due to the

• low ionization energy of sodium A
• sublimation of metallic sodium to give yellow vapour B
• emission of excess energy absorbed as a radiation in the visible region as a radiation in the visible region C
• photosenitivity D

When 6d orbital is complete, the entering electron goes into:

• 7f. A
• 7s. B
• 7p. C
• 7d. D

• Plank's equations A
• de Broglie's equations B
• Heisenburg's equation C
• None D

Energy of electron in the infinite Bohr orbit of H-atom is

• 0 KJ/mole A
• 1 KJ/mole B
• -1 KJ/mole C
• -1313.32 KJ/mole D