Chemistry Question Bank

The energy required to break one mole of Cl–Cl bonds in Cl₂ is 242 kJ mol⁻¹. The largest wavelength of light capable of breaking a single Cl–Cl bond is

The number of photons emitted in 10 hours by a 60 W sodium lamp (λ = 6000 Å) is approximately

The number of photons of light with wave number ν̄ = 2.5 × 10⁶ m⁻¹ necessary to provide 1 J of energy are

Which is NOT a characteristic of Planck's quantum theory of radiation?

Calculate the frequency of yellow radiation having wavelength 5800 Å.

Rutherford's nuclear model of the atom failed to explain

In the Rutherford scattering experiment, most α-particles passed straight through the gold foil because

The electrical discharge through gases could be observed only at

The e/m ratio for anode rays (positive rays) in comparison to cathode rays is:

[CBSE AIPMT 2015] The number of d-electrons in Fe²⁺ (Z = 26) is NOT equal to the number of electrons in which one of the following?

[CBSE AIPMT 2011] The energies E₁ and E₂ of two radiations are 25 eV and 50 eV respectively. The relation between their wavelengths λ₁ and λ₂ will be

[CBSE AIPMT 2011] If n = 6, the correct sequence of filling of electrons will be

[KCET 2010] The wave number of a spectral line in the emission spectrum of hydrogen will be equal to (8/9)R_H if the electron jumps from

[AMU 2010] When the electron of a hydrogen atom jumps from n = 4 to n = 1 state, the number of spectral lines emitted is

[CBSE AIPMT 2009] Which of the following is NOT a permissible arrangement of electrons in an atom?

[Manipal 2009] The uncertainty in position of an electron (m = 9.1 × 10⁻²⁸ g) moving with velocity 3.0 × 10⁴ cm s⁻¹ accurate to 0.011% will be (h = 6.626 × 10⁻²⁷ erg·s)

[AMU 2009] The radius of the Bohr orbit of the H-atom is r. Then the radius of the first orbit of Li²⁺ will be

[Haryana PMT 2009] The number of radial nodes of 3s and 2p-orbitals are respectively

[CBSE AIPMT 2008] If uncertainty in position and momentum are equal, then uncertainty in velocity is

Assertion (A): For Balmer series of hydrogen spectrum, the value of n₁ = 2 and n₂ = 3, 4, 5 ... Reason (R): The value of n for a line in Balmer series having the highest wavelength is n₁=4 and n₂=6.

The number of unpaired d-electrons retained in Fe²⁺ ion (At. no. of Fe = 26) is

The correct set of four quantum numbers for the valence electron of rubidium (Z = 37) is

Which of the following electronic transitions in a hydrogen atom will require the largest amount of energy?

The most probable radius (in pm) for finding the electron in He⁺ is

The velocity of an electron in the second shell of hydrogen atom is