List of top Chemistry Questions asked in KEAM

The critical temperature of some gases are: Methane 190K, ammonia 405K, carbon dioxide 304K, n-butane 425K and dihydrogen 33K. The gas that is adsorbed to the maximum extent on 1g of activated charcoal at a given temperature is

The half-life period of a first order reaction at 298K is 20 minutes. The time (in min.) required for 99.9% completion of the reaction at the same temperature, is

The vapour pressures of pure liquids X and Y at 350K are 200 mm and 300 mm of Hg respectively. Then the correct vapour pressure (in mm of Hg) of an ideal solution containing X and Y in the mole ratio 3: 2 at the same temperature is

The chemistry teacher asked the students to prepare 20% w/w solution of urea [NH₂CONH₂] in water. Which one of the following solution does not conform to the required composition?

The standard electrode potentials of some electrodes are given below:
Fe³⁺/Fe²⁺ 0.77V;   Br₂/Br^- 1.09V;    I₂/I^- 0.54V;    Zn²⁺/Zn(s) -0.76V;
Ag⁺/Ag(s) 0.80V;    Fe²⁺/Fe(s) -0.44V;    Cu²⁺/Cu(s) 0.34V
Predict the reaction that is not feasible:

The average oxidation number of bromine in Br₃O₈ is

The equilibrium constants for the following two reactions at 298k are given below:
2A ⇋ B+C; K₁ =16
2B + C ⇋ 2X; K₂ = 25
What is the value of k for the reaction, \(A+\frac{1}{2}B \rightleftharpoons X\) at 298K?

Some of the reactions and their equilibrium constants K_c are given. Choose the reaction which proceeds rarely at the given temperature.

Which one of the following is the correct relation between C_p and C_v for one mole of an ideal gas? (R is molar gas constant)

The standard enthalpy of formation of CH₄(g), CO₂(g) and H₂O(I) are -75 kJ mol^-1, -393 kJ mol^-1 and -286 kJ mol^-1 respectively. The amount of heat liberated (in kJ) when 3.2g of methane gas is burnt under standard conditions is

A metal 'X' crystallizes in a body-centered cubic structure and its metallic radius is 346.4 pm. The length (in pm) of the unit cell is

The dipole-dipole interaction energy between rotation polar molecules is proportional to___, where 'r' is the distance between polar molecules.

Which one of the following reactions involves change from sp² to sp³ hybridisation of the central atom?

Which one of the following molecules contains an incomplete octet of the central atom?

A fast moving particle of mass 6.63×10^-28g can be located with an accuracy of 1A. The uncertainty in its velocity (in ms^-1) is about (h=6.63×10^-34 Js)

From the following, choose the correct structures of chloroxylenol and terpineol, which are the constituents of "Dettol"

A particle of mass 6.6×10^-31kg is moving with a velocity of 1×10⁷ms^-1. The de Broglie wavelength (in A) associated with the particle, is (h=6.6×10^-34 Js)

A di-negative ion of the element X consists of 10 electrons and 8 neutrons. A dipositive ion of the element Y consists of 12 protons. The number of neutrons in Y is 1.5 times the number of electrons in atom X. Then the mass numbers of X and Y would be in the ratio

Among the following pairs of compounds, the one that does not illustrate the law of multiple proportions, is

Which one of the following contains the highest number of oxygen atoms?

A cooking gas contains carbon and hydrogen only. A volume of 11.2 L of this gas is found to weigh 22 g at STP. Then the molecular formula of the gas is

Among the following, the alkene that exhibits optical isomerism is

In the estimation of nitrogen present in an organic compound, Kjeldahl's method cannot be applied to

Which one of the following is an ore of aluminium?

The complex ion formed when the film developed in black and white photography is washed with hypo solution is