JEE Main Chemistry — Physical Chemistry previous year questions with solutions.
The de Broglie wavelength of a tennis ball of mass $60 \mathrm{~g}$ moving with a velocity of 10 metres per second is approximately
The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were $256 \mathrm{~g}$, the mass of it remaining undecayed after 18 hours would be
The enthalpy change for a reaction does not depend upon
In an irreversible process taking place at constant $\mathrm{T}$ and $\mathrm{P}$ and in which only pressure-volume work is being done, the change in Gibbs free energy (dG) and change in entropy (dS), satisfy the criteria
In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen
Standard reduction electrode potentials of three metals A,B\&C are respectively $+0.5 \mathrm{~V},-3.0 \mathrm{~V} \&-1.2 \mathrm{~V}$. The reducing, powers of these metals are
What volume of hydrogen gas, at $273 \mathrm{~K}$ and $1 \mathrm{~atm}$, pressure will be consumed in obtaining $21.6 \mathrm{~g}$ of elemental boron (atomic mass $=10.8$ ) from the reducti on of boron trichloride by hydrogen?
Which one of the following statements is not true?
A pressure cooker reduces cooking time for food because
Which one of the following groupings represents a collection of isoelectronic species? (At. nos,: 55, Br:35)
$25 \mathrm{ml}$ of a solution of barrium hydroxide on titration with a $0.1$ molar solution of hydrochloric acid gave a litre value of $35 \mathrm{ml}$. The molarity of barium hydroxide solution was
When rain is accompanied by a thunderstorm, the collected rain water will have a $\mathrm{pH}$ value
The orbital angular momentum for an electron revolving in an orbit is given by $\sqrt{l(l+1)} \cdot \frac{\mathrm{h}}{2 \pi}$. This momentum for an s-electron will be given by
Which of the following could act as apropellant for rockets?
For a cell reaction involving a two-electron change, the standard e.m.f. of the cell is found to be $0.295 \mathrm{~V}$ at $25^{\circ} \mathrm{C}$. The equilibrium constant of the reaction at $25^{\circ} \mathrm{C}$ will be
In a $0.2$ molal aqueous solution of a weak acid $\mathrm{HX}$ the degree of ionization is $0.3$. Taking $\mathrm{k}_{\mathrm{f}}$ for water as $1.85$, the freezing point of the solution will be nearest to
For the redox reaction $\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}^{2+}(0.1 \mathrm{M}) \rightarrow \mathrm{Zn}^{2+}(1 \mathrm{M})+\mathrm{Cu}(\mathrm{s})$ taking place in a cell, $\mathrm{E}_{\text {cell }}^0$ is $1.10$ volt. $\mathrm{E}^{\circ}$ for the cell will be $\left(2.303 \frac{\mathrm{RT}}{\mathrm{F}}=0.0591\right)$
The rate law for a reaction between the substances $\mathrm{A}$ and $\mathrm{B}$ is given by Rate $=\mathrm{k}[\mathrm{A}]^{\mathrm{n}}[\mathrm{B}]^{\mathrm{m}}$ On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as
The internal energy change when a system goes from state $\mathrm{A}$ to $\mathrm{B}$ is $40 \mathrm{~kJ} / \mathrm{mole}$. If the system goes from $\mathrm{A}$ to $\mathrm{B}$ by a reversible path and retums to state $\mathrm{A}$ by an irreversible path what would be the net change in internalenergy?
In a hydrogen atom, if energy of an electron in ground state is 13.6 eV, then that in the 2nd excited state is
If an endothermic reaction is non- spantaneous at freezing point of water and becomes feasible at its boiling point, then
Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively
The heat required to raise the temperature of body by 1 K is called
If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is