List of top Chemistry Questions on Spontaneity

Identify the correct statement from the following: 
UK 'copper' coins are Cu/Ni alloy. AgBr has special light-sensitive properties. Ti\(^{2+}\), V\(^{2+}\), Cr\(^{2+}\) are strong oxidising agents. The magnetic moment of V\(^{2+}\) is 2.84 BM.

Which of the following is present in the photochemical smog?

Match List I with List II

List IList II
APhysisorptioniSingle Layer Adsorption
BChemisorptionii20−40kJmol−1
CN2​(g)+3H2​(g)—⇢Fe(s)—⇢​2NH3​(g)iiiChromatography
DAnalytical Application or AdsorptionivHeterogeneous catalysis

Choose the correct answer from the options given below:

For independent processes at 300K
ProcessΔH/kJmol−1ΔS/JK−1
A-25-80
B-2240
C25-50
D2220

The number of non-spontaneous processes from the following is

Given are two statements one is labelled as Assertion A and other is labelled as Reason R.

Assertion A : Magnesium can reduce Al2O3 at a temperature below 1350°C, while above 1350°C aluminium can reduce MgO.
Reason R : The melting and boiling points of magnesium are lower than those of aluminium.

In light of the above statements, choose the most appropriate answer from the options given below :

When the same quantity of heat is absorbed by a system at two different temperatures $T_1$ and $T_2$, such that $T_1 > T_2$, change in entropies are $\Delta S_1$ and $\Delta S_2$ respectively. Then
The process with negative entropy change is :

The work done in ergs for the reversible expansion of one mole of an ideal gas from a volume of 10 liters to 20 liters at 25° is

The average translational kinetic energy of a molecule in a gas becomes equal to $0.69\, eV$ at a temperature about [Boltzmann constant = $1.38 \times 10^{-23} \; J \; K^{-1}$]
In which of the following changes entropy decreases.
A certain reaction is non spontaneous at 298K. The entropy change during the reaction is 121 $JK^{-1}.$ Is the reaction is endothermic or exothermic ? The minimum value of $\Delta$H for the reaction is
Molar enthalpy change for melting of ice is $6\, kJ / mol$. Then the internal energy change (in $k J / mol$ ) when $1$ mole of water is converted into ice at $1$ atm at $0^{\circ} C$ is Empty QImg
The entropy of vaporization of a liquid is $58 \, JK^{-1} \,mol^{-1}$. If $100\, g$ of its vapour condenses at its boiling point of $123^{\circ}C$, the value of entropy change for the process is (Molar mass of the liquid = $58 \,g \,mol^{-1})$
The entropy change involved in the isothermal reversible expansion of $2$ moles of an ideal gas from a volume of $10\, dm ^{3}$ at $27^{\circ} C$ is to a volume of $100\, dm ^{3}$
Predict in which of the following entropy decreases.
In which of the following reactions, standard entropy change $(\Delta S^{\circ})$ is positive and standard Gibb?s energy change $(\Delta G^{\circ})$ decreases sharply with increasing temperature ?
Standard entropies of $X_2 ,Y_2$ and $XY_3$ are $60 , 40 $ and $ 50 \, JK^{-1} mol^{-1}$ respectively. For the reaction $ { \frac{1}{2} X_2 + \frac{3}{2}Y_2 <=> XY_3, \Delta H = -30 kJ}$ to be at equilibrium, the temperature should be
Dissolution of ammonium chloride in water leads to a cooling sensation. At constant temperature, this process is accompanied by
The change in entropy for the fusion of $1$ mole of ice is [mp of ice = $273\, K$, molar enthalpy of fusion for ice $ = 6.0\,kJ\,mol^{-1} $ ]
Condition for spontaneity in an isothermal process is
The reaction,Zn(s) + CuSO4(aq) $\rightarrow$ZnSO4(aq) + Cu(s) is an example of a
For $A \longrightarrow B, \Delta H=4\, Cal\, mol ^{-1}\,\Delta S=10\, Cal\, mol ^{-1}\, K ^{-1}$ reaction is spontaneous when temperature can be :
The average translational energy and the rms speed of molecules in a sample of oxygen gas at 300 K are $6.21 \times 10^{-21}$ J and 484 m/s respectively. The corresponding values at 600 K are nearly (assuming ideal gas behaviour)
Calculate the entropy change in surroundings when \(1.00\ mol\) of \(H_2O(l)\) is formed under standard conditions. \(∆_fH^Θ= –286\ kJ mol^{-1}\).
Choose the reaction with negative $\Delta$S value