List of top Chemistry Questions asked in LPUNEST

For advertisement, the coloured discharge tubes contain
Which is the most basic oxide?
Assertion (A): Colloidal solution is electrically neutral. Reason (R): Due to similar nature of the charge carried by the particles, they repel each other and do not combine to form bigger particles.
Bond dissociation energies of \(XY,\;X_2\) and \(Y_2\) (all diatomic molecules) are in the ratio \(1:1:0.5\) and \(\Delta H_f\) of \(XY\) is \(-200\ \text{kJ mol}^{-1}\). The bond dissociation energy of \(X_2\) will be:
On the basis of information available for the reaction \[ \frac{4}{3}\,\text{Al} + \text{O}_2 \rightarrow \frac{2}{3}\,\text{Al}_2\text{O}_3, \quad \Delta G = -827\,\text{kJ mol}^{-1}\ \text{of } \text{O}_2, \] the minimum emf required to carry out electrolysis of \(\text{Al}_2\text{O}_3\) is: (Given \(1\,F = 96500\,\text{C}\))
Consider a successive reaction (all first order) \[ A \xrightarrow{k_1} B \xrightarrow{k_2} C \xrightarrow{k_3} D \] The incorrect statement is:
Van’t Hoff factors of aqueous solutions of \(X, Y, Z\) are \(1.8,\;0.8\) and \(2.5\) respectively. Hence, their:
The hybridization of atomic orbitals of N in NO$_2^-$, NO$_3^-$ and NH$_4^+$ are respectively
if ideal gas expands at constant temperature
A mixture of CO and CO$_2$ has vapour density 20 at STP. 100 g of this mixture contains ____ mole of CO
For the following question, enter the correct numerical value up to TWO decimal places. If the numerical value has more than two decimal places, round-off the value to TWO decimal places. (For example: Numerical value 5 will be written as 5.00 and 2.346 will be written as 2.35) Human blood gives rise to an osmotic pressure of approximately \(7.65\) atm at body temperature, \(37^\circ\text{C}\). Hence, molarity of an intravenous glucose solution to have the same osmotic pressure as blood is _____ M
For the following question, enter the correct numerical value up to TWO decimal places. If the numerical value has more than two decimal places, round-off the value to TWO decimal places. (For example: Numerical value 5 will be written as 5.00 and 2.346 will be written as 2.35) 20.4 g of \( \mathrm{H_2O_2} \) solution on decomposition gives 1.68 L of \( \mathrm{O_2} \) at STP. Percentage strength by weight of the solution is _____
For the following question, enter the correct numerical value up to TWO decimal places. If the numerical value has more than two decimal places, round-off the value to TWO decimal places. (For example: Numerical value 5 will be written as 5.00 and 2.346 will be written as 2.35) Elevation in boiling point of an aqueous urea solution is \(0.52^\circ\). (\(K_b = 0.52\,\text{mol}^{-1}\,\text{kg}\)). Hence, mole fraction of urea in this solution is _____
For the following question, enter the correct numerical value up to TWO decimal places. If the numerical value has more than two decimal places, round-off the value to TWO decimal places. (For example: Numerical value 5 will be written as 5.00 and 2.346 will be written as 2.35) The entropy of a sample of a certain substance increases by \(0.836\,\text{J K}^{-1}\) on adding reversibly \(0.3344\,\text{J}\) of heat at constant temperature. The temperature of the sample is _____ K
For the following question, enter the correct numerical value up to TWO decimal places. If the numerical value has more than two decimal places, round-off the value to TWO decimal places. (For example: Numerical value 5 will be written as 5.00 and 2.346 will be written as 2.35) A diatomic molecule has a dipole moment of \(1.2\,\text{D}\). If the bond distance is \(1.0\,\text{\AA}\), the fraction of an electronic charge on each atom is _____
Intensive property among the following is:
Given the following reaction at equilibrium \(N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)\). Some inert gas at constant pressure is added to the system. Predict which of the following facts will be affected.
Ratio of average kinetic energies of equal masses of \(H_2\) and \(He\) at the same temperature is
Which has the highest boiling point?
In which pair or pairs is the stronger bond found in the first species? I: \(O_2^{2-},\, O_2\)
II: \(N_2,\, N_2^+\)
III: \(NO^+,\, NO\)
Probability of finding electron in YZ plane for \(p_x\) orbital is:
Orbital angular momentum of electron in \(p\) orbital is equal to
The ratio of velocities of two photons of wavelengths \(2000\,\text{\AA}\) and \(4000\,\text{\AA}\) is
Consider the following data: \(\Delta_f H^\circ (N_2H_4, l) = 50\,\text{kJ mol}^{-1}\), \(\Delta_f H^\circ (NH_3, g) = -46\,\text{kJ mol}^{-1}\), Bond energy \( \text{B.E.}(N-H) = 393\,\text{kJ mol}^{-1}\) and \(\text{B.E.}(H-H) = 436\,\text{kJ mol}^{-1}\), \(\Delta_{vap} H (N_2H_4, l) = 18\,\text{kJ mol}^{-1}\). The \(N-N\) bond energy in \(N_2H_4\) is
Variation of \(\log_{10} K\) with \(\dfrac{1}{T}\) is shown by the following graph in which straight line is at \(45^\circ\). Hence \(\Delta H^\circ\) is: