Welcome to your chem set -3
1.
The number of moles of KMnO₄ reduced by one mole of KI in alkaline medium is
2.
The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is
3.
In the Haber process, 30L of dihydrogen and 30L of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the composition of gaseous mixture under the aforesaid condition in the end?
4.
Which has the maximum number of molecules?
5.
Assuming fully decomposed, the volume of CO₂ released at STP on heating 9.85 g of BaCO₃ (at. mass of Ba = 137) will be
6.
In the reaction, 4NH₃(g) + 3O₂(g) → 4NO(g) + 6H₂O(l), when 1 mole of ammonia and 1 mole of O₂ are made to react to completion, then
7.
Liquid benzene (C₆H₆) burns in oxygen: 2C₆H₆(l) + 15O₂(g) ⟶ 12CO₂(g) + 6H₂O(g). How many litres of O₂ at STP are needed to complete the combustion of 39 g of benzene? (C₆H₆ = 78)
8.
What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene? (C₂H₄)
9.
One litre hard water contains 12.00 mg Mg²⁺. Milliequivalents of washing soda required to remove its hardness is?
10.
Which of the following is never true for cathode rays?
11.
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:
12.
The energy absorbed by each molecule (A₂) of a substance is 4.4 × 10⁻¹⁹ J and bond energy per molecule is 4.0 × 10⁻¹⁹ J. The kinetic energy of the molecule per atom will be:
13.
The energy of second Bohr orbit of the hydrogen atom is –328 kJ/mol, hence the energy of fourth Bohr orbit would be:
14.
The frequency of radiation emitted when the electron falls from n = 4 to n = 1 in a hydrogen atom will be (Given: ionisation energy of H = 2.18 × 10⁻¹⁸ J/atom, h = 6.625 × 10⁻³⁴ Js)
15.
In hydrogen atom, energy of first excited state is –3.4 eV. Then, kinetic energy (KE) of the same orbit of hydrogen atom is:
16.
Who modified Bohr’s theory by introducing elliptical orbits for electron path?
17.
Bohr radius for the hydrogen atom (n = 1) is approximately 0.530 Å. The radius for the first excited state (n = 2) is (in Å):
18.
The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li²⁺ ion (atomic number = 3) in a similar state is:
19.
When an electron of charge e and mass m moves with a velocity v about the nuclear charge Ze in a circular orbit of radius r, the potential energy of the electron is given by:
20.
If ionisation potential for hydrogen atom is 13.6 eV, then ionisation potential for He⁺ will be:
21.
The energy of an electron in the n-th Bohr orbit of hydrogen atom is:
22.
Which of the following statements do not form a part of Bohr’s model of the hydrogen atom?
23.
If r is the radius of the first orbit, the radius of the n-th orbit of H-atom is given by:
24.
The spectrum of helium is expected to be similar to that of:
25.
A particular station of All India Radio, New Delhi, broadcasts on a frequency of 1,368 kHz. The wavelength of the electromagnetic radiation emitted by the transmitter is: (Speed of light, c = 3.0 × 10⁸ m/s)
26.
In hydrogen atom, the de-Broglie wavelength of an electron in the second Bohr orbit is: (Given: Bohr radius a₀ = 0.529 pm)
27.
Which one is the wrong statement?
28.
How many electrons can fit in the orbital for which n = 3 and l = 1?
29.
The number of d-electrons in Fe²⁺ (Z = 26) is not equal to the number of electrons in which one of the following?
30.
The angular momentum of electrons in d-orbital is equal to:
31.
Calculate the energy (in joules) corresponding to light of wavelength 45 nm. (Given: h = 6.63 × 10⁻³⁴ Js, c = 3 × 10⁸ m/s)
32.
The value of Planck’s constant is 6.63 × 10⁻³⁴ Js. The speed of light is 3 × 10¹⁷ nm/s. Which value is closest to the wavelength in nanometers of a quantum of light with frequency 6 × 10¹⁵ s⁻¹?
33.
The measurement of the electron position is associated with an uncertainty in momentum equal to 1 × 10⁻¹⁸ g·cm/s. The uncertainty in electron velocity is (mass of electron = 9 × 10⁻²⁸ g):
34.
If uncertainty in position and momentum are equal, then the uncertainty in velocity is:
35.
Given: mass of electron = 9.11 × 10⁻³¹ kg, Planck’s constant = 6.626 × 10⁻³⁴ Js. The uncertainty in velocity when position is known within 0.1 Å is:
36.
The value of Planck’s constant is 6.63 × 10⁻³⁴ Js. The velocity of light is 3.0 × 10⁸ m/s. Which value is closest to the wavelength in nanometers of a quantum of light with frequency 8 × 10¹⁵ s⁻¹?
37.
The energy of a photon is given as ΔE = 3.03 × 10⁻¹⁹ J/atom. What is the wavelength (λ) of the photon? (Given: h = 6.63 × 10⁻³⁴ Js, c = 3.00 × 10⁸ m/s)
38.
The de-Broglie wavelength of a particle with mass 1 g and velocity 100 m/s is:
39.
The uncertainty in momentum of an electron is 1 × 10⁻²⁵ kg·m/s. What is the uncertainty in its position? (Given: h = 6.62 × 10⁻³⁴ kg·m²/s)
40.
The position of both, an electron and a helium atom, is known within 1.0 mm. Further, the momentum of the electron is known within 5.0 × 10⁻²⁶ kg·m/s. The minimum uncertainty in the measurement of the momentum of the helium atom is:
41.
The momentum of a particle having a de-Broglie wavelength of 10⁻¹⁷ m is (Given: h = 6.625 × 10⁻³⁴ Js):
42.
The uncertainty in the position of an electron (mass = 9.1 × 10⁻²⁸ g) moving with a velocity of 3 × 10⁴ cm/s, accurate up to 0.001%. (Use h / 4π in uncertainty, where h = 6.626 × 10⁻²⁷ erg·s):
43.
In the photoelectron emission, the energy of the emitted electron is:
44.
The electron was shown experimentally to have wave properties by:
45.
The number of angular nodes and radial nodes in 3s orbital are:
