ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

Charge of an electron is:

• 1.6 x 10^-19 C

  A

• 9.1 x 10^-34 C

  B

• 1.7588 x 10¹¹ C

  C

• 6.62 x 10^-34 C

  D

The divisibility of atom was shown by

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

When an electric current is passed through discharge tube at low pressure, cathode rays are emitted from cathode these rays consist of:

• Alpha rays. A
• Negative particles. B
• Electromagnetic rays. C
• Positive particles. D

Neutrons was discovered by

• Mosely A
• Milliken B
• Chadwick C
• Ruherford D

Alpha rays consist of:

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

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

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 degenerate orbitals p-sub shell are

• 2 A
• 3 B
• 5 C
• 7 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

Orbitals having same energy are called

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

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 third line of the Balmer series, in the emission spectrum of the hydrogen atom,is due to the transition from the

• Fourth Bohr orbit to the first Bohr orbit A
• Fifth Bohr orbit to the second Bohr orbit B
• Sixth Bohr orbit to the third Bohr orbit C
• Seventh Bohr orbit to the third Bohr orbit D

n + l value for 4f will

• 2 A
• 5 B
• 7 C
• 9 D

The mass of the neutron is of the order of

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

Orbital having same energy is called:

• Hybrid orbital. A
• Valence orbital. B
• Degenerate orbital. C
• D-orbital. 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

The atomic number of an element is 35 what is the total number of electrons present in all the p-orbitals of the ground state atom of that element?

• 6 A
• 11 B
• 17 C
• 23 D

If the radius of first Bohr orbit be a_o, then the radius of third Bohr orbit would be

• 3 x a_o A
• 6 x a_o B
• 9 x a_o C
• 1/2 x a_o D

The wave number of light emitted by a certain source is 2 x 10⁵m. The wavelength of this light will be:

• 500 NM. A
• 500 M. B
• 200 NM. C
• 5 x 10⁷m D

Which of the following has more unpaired d-electrons?

• Zn⁺ A
• Fe²⁺ B
• Ni³⁺ C
• Cu⁺ D

The wave number of the line emitted is 109.678 x 10⁵m^-1in the Lyman series when electron transition occurs

• 
  A
• 
  B
• 
  C
• 
  D

For which of the following sets of quantum numbers and electron will have the highest energy?

• 3,2,1,1/2 A
• 4,2,-1,1/2 B
• 4,1,0,-1/2 C
• 5,0,0,1/2 D

The limiting line of Blamer series in hydrogen spectrum lies in

• Visible regions A
• Ultraviolet region B
• Infrared region C
• x-rays region D

The charge of an electron is determined by

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

The total values of magnetic quantum number of subshell are five, the subshell is

• S-subshell A
• P-subshell B
• D-subshell C
• F-subshell D

1 erg of energy corresponds to

• 6.02 x 10²³J/mol A
• 6.02 x 10¹⁶J/mol B
• 1 erg/mol C
• 10^-7J/mol D

Cathode rays emitted from cathode are

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