AIIMS Chemistry Thermodynamics Class 11 Questions

1 mole of a diatomic is heated through isochoric process from 300 k to 500 K. The entropy is :

Assertion : Air that quickly leaks out of a balloon becomes cooler.

Reason : The leaking air undergoes adiabatic expansion.

Assertion : U is a state function.

Reason : T is an intensive property.

Assertion : In a process, if $\text{work} = 0$ then $\Delta U = q$.

Reason : $q$ is the difference between the initial state and final state of a system.

The correct relation is:

One mole of a non-ideal gas undergoes a change of state $(2.0\text{ atm},\ 3.0\text{ L},\ 95\text{ K}) \rightarrow (4.0\text{ atm},\ 5.0\text{ L},\ 245\text{ K})$ with a change in internal energy, $\Delta\text{U} = 30.0\text{ L atm}$. The change in enthalpy $\Delta\text{H}$ of the process in $\text{L atm}$ is.

Assertion : The graph between $\text{P}$ v/s $\frac{1}{\text{V}}$ is a straight line.

Reason : The anionic sites occupied by unpaired electrons (due to F-centres)

In conversion of lime-stone to lime,

$\text{CaCO}_3(\text{s}) \rightarrow \text{CaO}(\text{s}) + \text{CO}_2(\text{g})$

he values of $\Delta\text{H}^\circ$ and $\Delta\text{S}^\circ$ are $+179.1\text{ kJ mol}^{-1}$ and $160.2\text{ J/K}$ respectively at $298\text{ K}$ and $1\text{ bar}$. Assuming that $\Delta\text{H}^\circ$ and $\Delta\text{S}^\circ$ do not change with temperature, temperature above which conversion of lime-stone to lime will be spontaneous is

Here is the extracted question and its options formatted for your frontend and database.Rendered TextQuestion 98:If Boiling point of water is $100^\circ\text{C}$. How much gram of $\text{NaCl}$ is added in $500\text{ g}$ of water to increase the boiling point of water by approx. $1^\circ\text{C}$. $(K_b)_{\text{H}_2\text{O}} = 0.52\text{ K}\cdot\text{kg/mole}$

A bulb is emitted electromagnetic radiation of 660 nm wavelength. The Total energy of radiation is ${3 \times10^{-18}}$ The number of emitted photon will be : ($\text{h} = 6.6 \times 10^{-34} \text{ J} \times \text{s}, \text{C} = 3 \times 10^8 \text{ m/s}$)

What is the activation energy (KJ/mol) for a reaction if its rate constant doubles when the temperature is raised from 300 K to 400 K ? $(R = 8.314 \text{ J mol}^{-1} \text{ K}^{-1})$

Assertion : At equilibrium, $\Delta G = 0$.

Reason : At equilibrium, $\Delta G^0 = RT \log K_c$.

At critical state, the compressibility factor (Z) for a real gas is equal to

Ideal gas 1 mole expand isothermally reversibly 2 lt. to 4lt and same gas 3 mole expand from 2 lt. to x lt and doing same work, what is ‘x’

Gas in a cylinder is maintained at $10\text{ atm}$ pressure and $300\text{ K}$ temperature. The cylinder will explode if the pressure of the gas goes beyond $15\text{ atm}$. What is the maximum temperature to which the gas can be heated?

In which process volume increases

Which of following factor always increases for spontaneous process

What is the entropy change in $2\text{ mol}$ of $\text{N}_2$, when its temperature is taken from $400\text{ K}$ to $800\text{ K}$, adiabatically.

Calculate work done

Assertion : In free expansion, $\Delta U = 0$

Reason : No work is done in free expansion.

Correct order of acidic strength

Assertion : When ideal gas expand from $P_1, V_1, T_1$ to $P_2, V_2, T_2$ in two steps, and work done is high in which number of steps are high

Reason : Work is path function

Assertion : For an isothermal process involving an ideal gas Gibbs and Helmholtz free energy changes are equal, i. e. $\Delta G = \Delta A$.

Reason : In an isothermal process for an ideal gas system both $\Delta E$ and $\Delta H$ are zero.

Determine ΔG° for the following reaction: CO(g) + ½ O₂(g) → CO₂(g) ΔH° = −282.84 kJ given, S°CO₂ = 213.8 S°O₂ = 205.8 J/K/mol

For the reaction:

$\text{A}_2(\text{g}) + 4\text{B}_2(\text{g}) \rightleftharpoons 2\text{AB}_4(\text{g}), \quad \Delta\text{H} < 0$

the formation of $\text{AB}_4$ will be favoured at:

ΔG° versus T plot the Ellingham’s diagram slopes downward for the reaction

The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from a volume of 10 dm³ at 27°C is to a volume of 100 dm³

Bond dissociation energy of CH₄ is 360 kJ/mol and C₂H₆ is 620 kJ/mol. Then bond dissociation energy of C—C bond is

Assertion: In a pressure cooker, the water is brought to boil. The cooker is then removed from the stove. Now on removing the lid of pressure cooker, the water starts boiling again. Reason: The impurities in water bring down its boiling point.

The enthalpy of formation of CO(g), CO₂(g), N₂O(g) and N₂O₄(g) i$s^{-110}$, -393, +81 and 10 kJ/mol respectively. For the reaction, N₂O₄(g) + 3CO(g) → N₂(g) + 3CO₂(g), ΔHᵣ (kJ/mol) is

Assertion : Heat of neutralisation of nitric acid with NaOH is same to that of HCl and NaOH. Reason : In both cases strong acid and strong bases are neutralised. H⁺ + OH⁻ → H₂O.

Assertion : A reaction which is spontaneous and accompanied by decrease of randomness must be exothermic. Reason : All exothermic reactions are accompanied by decrease of randomness.

Assertion: Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.

Reason: Entropy of the system increases with increase in temperature.

Assertion : As a salt such as NaCl dissolves, the Na⁺ and Cl⁻ ions leaving the crystal lattice acquire far greater freedom.

Reason : In thermodynamic terms, the formation of solution occurs with a favourable change in free energy, i.e., ΔH has a high positive value and TΔS a low negative value.

Assertion : Water in liquid state is more stable than ice at room temperature.

Reason : Water in liquid form has higher entropy than ice.

For the chemical equilibrium, CaCO₃(s) ⇌ CaO(s) + CO₂(g), ΔH°f can be determined from which one of the following plots?

How much energy is released when 6 moles of octane is burnt in air? Given ΔHf° for CO₂(g), H₂O(g) and C₈H₁₈(g) respectively ar$e^{-490}$, -240 and +160 kJ/mol.

Assertion : Molar entropy of vaporisation of water is different from ethanol.

Reason : Water is more polar than ethanol.

One gram sample of NH₄NO₃ is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K. The heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for NH₄NO₃?

Assertion : The increase in internal energy (ΔE) for the vaporization of one mole of water at 1 atm and 373 K is zero.

Reason : For all isothermal processes, ΔE = 0.

Assertion : ΔH and ΔE are almost the same for the reaction, N₂ (g) + O₂ (g) ⇌ 2NO (g).

Reason : All reactants and products are gases.

The heat of neutralization of a strong base and a strong acid is 57 kJ. The heat released when 0.5 mole of HNO₃ solution is added to 0.20 moles of NaOH solution, is

Assertion : During an adiabatic process, heat energy is not exchanged between system and its surroundings.

Reason : The temperature of a gas increases when it undergoes an adiabatic expansion.

Assertion : An increase in surface area increases the rate of evaporation.

Reason : Stronger the inter-molecular attractive forces, fast is the rate of evaporation at a given temperature.

Assertion : Mass and volume are extensive properties.

Reason : Mass/volume is also an extensive parameter.

Assertion : Absolute values of internal energy of substances can not be determined.

Reason : It is impossible to determine exact values of constituent energies of the substances.

Which of the following is always feasible? ΔH = TΔS

Given that C + O₂ → CO₂ ; ΔH⁰ = −a kJ. 2CO + O₂ → 2CO₂ ; ΔH⁰ = −b kJ The heat of formation of CO is

The combustion enthalpies of carbon, hydrogen and methane are −395.5 kJ mol⁻¹, −284.8 kJ mol⁻¹ and −890.4 kJ mol⁻¹ respectively at 25°C. The value of standard formation enthalpies of methane at that temperature is

Assertion: Heat of neutralization for both HNO₃ and HCl with NaOH is 53.7 KJ/mole.

Reason: NaOH is a strong electrolyte/base.