List of practice Questions

The first order reaction \(N_2O_5 \to 2NO_2 + 1/2 O_2\), is carried out in a closed container and there were no products initially. When it is heated at constant volume the final pressure of the system on 75% completion of the reaction is

List-I contains some group-I elements and List-II contains their electron gain enthalpy values (in kJ mol\(^{-1}\))
List-I: (i) H, (ii) Li, (iii) Na, (iv) K
List-II: (a) -48, (b) -53, (c) -73, (d) -60
Choose the correct match.

The molecule with the highest dipole moment among the following is

The covalent bond length is almost the same in which of the following pairs of bonds

Which of the following substance has the standard molar enthalpy of formation zero?

The molar entropy of which of the following reaction is negative?

A certain amount of H$_{2(g)}$ and I$_{2(g)}$ are sealed in a 4L container and kept at 600K to attain equilibrium. K$_C$ for the reaction, H$_{2(g)}$ + I$_{2(g)} \rightleftharpoons$ 2HI\(_{(g)}\) at 600K is 64. If the equilibrium concentration of HI\(_{(g)}\) is 0.08M, what are the equilibrium concentrations of H$_{2(g)}$ and I$_{2(g)}$ at the same temperature?

Choose the correct statement

2.8 g of N$_{2(g)}$ and 0.8 g of H$_{2(g)}$ are allowed to react completely. What is the mass of NH$_{3(g)}$ formed? (molar mass of N$_{2(g)}$=28, H$_{2(g)}$=2 and NH$_{3(g)}$=17)}

Consider the following statements about photoelectric effect:
(i) There is time lag between the striking of light beam and the ejection of electrons from the metal surface.
(ii) The number of electrons ejected is directly proportional to the intensity or brightness of light.
(iii) For each metal, there is a characteristic minimum frequency, known as threshold frequency (\(\nu_0\)) below which photoelectric effect is not observed.
(iv) At a frequency greater than \(\nu_0\), the ejected electrons come out with certain kinetic energy. The kinetic energies of these electrons increase with the increase of the wavelength of the light used.
Which of the above statements are true?

According to Bohr's theory the radius of the second stationary state of hydrogen atom is

The correct decreasing order of the first ionization enthalpies among the elements C, N, O, F is

Two convex lenses of different focal lengths are in contact with each other. If the focal length of each lens is doubled, the focal power of the combination

Two light rays of wavelength \(\lambda\) and \(\frac{\lambda}{4}\) incident on the surface of a photo sensitive material emit electrons with max kinetic energy \(E\) and \(6E\) respectively. The work function of the material is (\(h\) = Planck’s constant, \(c\) = velocity of light in free space)

For the same kinetic energy, the de Broglie wavelengths associated with particles of different masses are

In hydrogen spectral series, the wave numbers of the first Lyman line and the first Balmer line are in the ratio

1600 atoms of a radioactive substance with a half life period \(T\) start decaying at \(t=0\). The time during which 1550 atoms would have decayed is

In the energy band diagram of solids, if the conduction band and the valance band overlap, the solid is

The magnetic susceptibility of a diamagnetic material is

The mutual inductance between a pair of coils is 3 H. If the current in one coil changes from 0 A to 2 A in 0.5 s, the induced emf produced in the other coil is

A pure inductor of self inductance 500 mH is connected to an alternating voltage supply of \(100\sqrt{2}\pi \sin 100\pi t\) volt. The current in the circuit in ampere is

A radio can tune in to any station in the 7.5 MHz to 12 MHz band. The corresponding wavelength band is

The refractive index of the material of a glass prism of refracting angle \(60^\circ\) and angle of minimum deviation \(30^\circ\) is

In Young’s double slit experiment, the screen is placed 1m away from the coherent sources. If the wavelength of light used changes from 500 nm to 600 nm the fringe width increases by 0.25mm. The distance between the slits in mm is

5 equal resistors are combined suitably to get maximum and minimum effective resistances. Their ratio is