ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

Energy of electron in first orbit of H atom is

• -45.32 KJ/mole A
• -82.08 KJ/mole B
• -52.53 KJ/mole C
• -1313.31 KJ/mole D

The mass of the neutron is of the order of

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

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

• n A
• n² B
• 2n C
• 2n² D

Effective magnetic moment of Sc³⁺ion is

• 1.73 A
• 0 B
• 5.92 C
• 2.83 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

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

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

Mass of simple electron is:

• 9.1 x 10^-31 kg

  A

• 9.1 x 10^-30 kg

  B

• 1.66 x 10^-31 kg

  C

• 9.1 x 10^-31 kg

  D

n + l value for 4f will

• 2 A
• 5 B
• 7 C
• 9 D

The total number of possible values of magnetic quantum number for the value of l=3 is

• 3 A
• 1 B
• 5 C
• 7 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

Which of the following was discovered first:

• Charge to mass ratio of electrons. A
• Mass of electrons. B
• Charge of electrons. C
• All of above at same time. D

The divisibility of atom was shown by

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

Balmer's series is in ______ region

• Visible A
• U V B
• I. R. C
• None D

Orbital having same energy is called:

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

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

Which of the following is not charged particle

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

Which of the following has more unpaired d-electrons?

• Zn⁺ A
• Fe²⁺ B
• Ni³⁺ C
• Cu⁺ 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

Which of the following element's outermost orbits last electron has magnetic quantum number m=0?

• Na A
• O B
• Cl C
• N D

The electron in an atom

• moves randomly around the nucleus A
• has fixed space around the nucleus B
• is stationary in various energy levels C
• moves around its nucleus in definite energy levels D

The total number of orbitals in a shell with principal quantum number 'n' is

• 2n A
• 2n² B
• n² C
• n + 1 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

The limiting line of Blamer series in hydrogen spectrum lies in

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

Which quantum number is sufficient to describe the electron is hydrogen atom?

• l A
• n B
• m C
• s D

Which one of the following particles has amass 1/1836 time, that of hydrogen?

• Neutron. A
• Proton. B
• Electron. C
• Positron. D

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

• 7f A
• 7 s B
• 7 p C
• 7 d D

The value of R (Rydberg's constant) is _______ m-1

• 1.0974 x 107 A
• 1.0842 x 107 B
• 1.082 x 10-7 C
• Both a and b 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 size of electronic shell is described by

• Azimuthal Q. no A
• Magnetic Q.No B
• Spin Q. No C
• Principle Q. No D