Samacheer Kalvi solutions for Chemistry - Volume 1 and 2 [English] Class 11 TN Board chapter 7 - Thermodynamics [Latest edition]

The amount of heat exchanged with the surrounding at constant pressure is given by the quantity

All the naturally occurring processes proceed spontaneously in a direction which leads to

In an adiabatic process, which of the following is true?

In a reversible process, the change in entropy of the universe is

In an adiabatic expansion of an ideal gas

The intensive property among the quantities below is

An ideal gas expands from the volume of 1 × 10^–3 m³ to 1 × 10^–2 m³ at 300 K against a constant pressure at 1 × 10⁵ Nm^–2. The work done is

Heat of combustion is always ___________.

The heat of formation of CO and CO₂ are – 26.4 kCal and – 94 kCal, respectively. Heat of combustion of carbon monoxide will be

C(diamond) → C(graphite), ∆H = –ve, this indicates that

The enthalpies of the formation of Al₂O₃ and Cr₂O₃ are – 1596 kJ and – 1134 kJ, respectively. ∆H for the reaction \[\ce{2Al + Cr2O3 -> 2Cr + Al2O3}\] is

Which of the following is not a thermodynamic function?

If one mole of ammonia and one mole of hydrogen chloride are mixed in a closed container to form ammonium chloride gas, then

Change in internal energy, when 4 kJ of work is done on the system and 1 kJ of heat is given out by the system is

The work done by the liberated gas when 55.85 g of iron (molar mass 55.85 g mol^–1) reacts with hydrochloric acid in an open beaker at 25°C

The value of ∆H for cooling 2 moles of an ideal monatomic gas from 125°C to 25°C at constant pressure will be `["given C"_"P" = 5/2"R"]`

Given that \[\ce{C_{(g)} + O2_{(g)} -> CO2_{(g)}}\] ∆H° = – a kJ; \[\ce{2CO_{(g)} + O2_{(g)} -> 2CO2_{(g)}}\] ∆H° = – b kJ; Calculate the ∆H° for the reaction \[\ce{C_{(g)} + 1/2O2_{(g)} -> CO_{(g)}}\]

When 15.68 litres of a gas mixture of methane and propane are fully combusted at 0°C and 1 atmosphere, 32 litres of oxygen at the same temperature and pressure are consumed. The amount of heat released from this combustion in kJ is (∆H_C(CH₄) = – 890 kJ mol⁻¹ and ∆H_C(C₃H₈) = – 2220 kJ mol⁻¹)

The bond dissociation energy of methane and ethane are 360 kJ mol^–1 and 620 kJ mol^–1 respectively. Then, the bond dissociation energy of the C-C bond is

The correct thermodynamic conditions for the spontaneous reaction at all temperature is

The temperature of the system, decreases in an ___________.

In an isothermal reversible compression of an ideal gas the sign of q, ∆S and w are respectively

Molar heat of vapourisation of a liquid is 4.8 kJ mol^–1. If the entropy change is 16 J mol^–1 K^–1, the boiling point of the liquid is

∆S is expected to be maximum for the reaction

The values of ∆H and ∆S for a reaction are respectively 30 kJ mol^–1 and 100 JK^–1 mol^–1. Then the temperature above which the reaction will become spontaneous is

Answer the following in one or two sentences.

State the first law of thermodynamics.

Define Hess's law of constant heat summation.

Explain intensive properties with two examples.

Define the following term:

Isothermal process

Define the following term:

Adiabatic process

Define the following term:

Isobaric process

Define the following term:

Isochoric process

What is the usual definition of entropy?

What is the unit of entropy?

Predict the feasibility of a reaction when both ΔH and ΔS positive.

Predict the feasibility of a reaction when both ΔH and ΔS negative.

Predict the feasibility of a reaction when ΔH decreases but ΔS increases.

Define is Gibb’s free energy.

Define enthalpy of combustion.

Define molar heat capacity.

Write the unit of molar heat capacity.

Define the calorific value of food.

What is the unit of calorific value?

Define enthalpy of neutralization.

What is lattice energy?

What are state and path functions? Give two examples.

Give Kelvin a statement of the second law of thermodynamics.

The equilibrium constant of a reaction is 10, what will be the sign of ∆G? Will this reaction be spontaneous?

Enthalpy of neutralization is always a constant when a strong acid is neutralized by a strong base: account for the statement.

State the third law of thermodynamics.

Write down the Born-Haber cycle for the formation of CaCl₂

Identify the state and path functions out of the following:

1. Enthalpy
2. Entropy
3. Heat
4. Temperature
5. Work
6. Free energy

State the various statements of the second law of thermodynamics.

What are spontaneous reactions?

What are the conditions for the spontaneity of a process?

List the characteristics of internal energy.

Explain how heat absorbed at constant volume is measured using a bomb calorimeter with a neat diagram.

Calculate the work involved in the expansion and compression process.

Derive the relation between ∆H and ∆U for an ideal gas. Explain each term involved in the equation.

Suggest and explain an indirect method to calculate lattice enthalpy of sodium chloride crystal.

List the characteristics of Gibbs free energy.

Calculate the work done when 2 moles of an ideal gas expands reversibly and isothermally from a volume of 500 ml to a volume of 2 L at 25°C and normal pressure.

In a constant volume calorimeter, 3.5 g of gas with molecular weight 28 was burnt in excess oxygen at 298 K. The temperature of the calorimeter was found to increase from 298 K to 298.45 K due to the combustion process. Given that the calorimeter constant is 2.5 kJ K⁻¹. Calculate the enthalpy of combustion of the gas in kJ mol⁻¹.

Calculate the entropy change in the system, and surroundings, and the total entropy change in the universe during a process in which 245 J of heat flows out of the system at 77°C to the surrounding at 33°C.

1 mole of an ideal gas, maintained at 4.1 atm and at a certain temperature, absorbs heat 3710 J and expands to 2 litres. Calculate the entropy change in the expansion process.

30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK⁻¹ mol⁻¹. Calculate the melting point of sodium chloride.

Calculate the standard heat of formation of propane, if its heat of combustion is −2220.2 kJ mol⁻¹ the heats of formation of \[\ce{CO2_{(g)}}\] and \[\ce{H2O_{(l)}}\] are −393.5 and −285.8 kJ mol⁻¹ respectively.

You are given normal boiling points and standard enthalpies of vapourisation. Calculate the entropy of vapourisation of liquids listed below.

You are given normal boiling points and standard enthalpies of vapourisation. Calculate the entropy of vapourisation of liquids listed below.

For the reaction \[\ce{Ag2O_{(s)} -> 2Ag_{(s)} + 1/2O2_{(g)}}\]: ΔH = 30.56 kJ mol⁻¹ and ΔS = 6.66 JK⁻¹ mol⁻¹ (at 1 atm). Calculate the temperature at which ΔG is equal to zero. Also predict the direction of the reaction

1. at this temperature and
2. below this temperature.

What is the equilibrium constant K_eq for the following reaction at 400 K?

\[\ce{2NOCl_{(g)} ⇌ 2NO_{(g)} + Cl2_{(g)}}\], given that H⁰ = 77.2 kJ mol⁻¹ and ∆S⁰ = 122 JK⁻¹ mol⁻¹

Cyanamide (NH₂CN) is completely burnt in excess oxygen in a bomb calorimeter, ΔU was found to be −742.4 kJ mol⁻¹, calculate the enthalpy change of the reaction at 298 K.\[\ce{NH2CN_{(s)} + 3/2 O2_{(g)} -> N2_{(g)} + CO2_{(g)} + H2O_{(l)}}\] ΔH = ?

Calculate the enthalpy of hydrogenation of ethylene from the following data.

Bond energies of C − H, C − C, C = C and H − H are 414, 347, 618 and 435 kJ mol⁻¹.

Calculate the lattice energy of CaCl₂ from the given data

\[\ce{Ca_{(s)} + Cl2_{(g)} -> CaCl2_{(s)}}\] ∆`"H"_"f"^0` = − 795 kJ mol⁻¹

Sublimation: \[\ce{Ca_{(s)} -> Ca-{(g)}}\] ∆`"H"_1^0` = + 121 kJ mol⁻¹

Ionisation: \[\ce{Ca_{(g)} -> Ca^2+_{(g)} + 2e^-}\] ∆`"H"_2^0` = + 2422 kJ mol⁻¹

Dissociation: \[\ce{Cl2_{(g)} -> 2Cl_{(g)}}\] ∆`"H"_3^0` = + 242.8 kJ mol⁻¹

Electron affinity: \[\ce{Cl_{(g)} + e^- -> Cl^-_{(g)}}\] ∆`"H"_4^0` = −355 kJ mol⁻¹

Calculate the enthalpy change for the reaction \[\ce{Fe2O3 + 3CO -> 2Fe + 3CO2}\] from the following data.

\[\ce{2Fe + 3/2O2 -> Fe2O3}\]; ΔH = −741 kJ

\[\ce{C + 1/2O2 -> CO}\]; ΔH = −137 kJ

\[\ce{C + O2-> CO2}\]; ΔH = −394.5 kJ

When 1-pentyne (A) is treated with 4N alcoholic KOH at 175°C, it is converted slowly into an equilibrium mixture of 1.3% 1-pentyne (A), 95.2% 2-pentyne (B) and 3.5% of 1, 2 pentadiene (C) the equilibrium was maintained at 175°C, calculate ΔG⁰ for the following equilibria.

\[\ce{B ⇌ A}\] `Δ"G"_1^0` = ?

\[\ce{B ⇌ C}\] `Δ"G"_2^0` = ?

At 33K, N₂O₄ is fifty percent dissociated. Calculate the standard free energy change at this temperature and at one atmosphere.

The standard enthalpies of formation of SO₂ and SO₃ are −297 kJ mol⁻¹ and −396 kJ mol⁻¹ respectively. Calculate the standard enthalpy of reaction for the reaction: \[\ce{SO2 + 1/2O2 -> SO3}\]

For the reaction at 298 K: \[\ce{2A + B -> C}\]

ΔH = 400 KJ mol⁻¹; ΔS = 0.2 KJ K⁻¹ mol⁻¹ Determine the temperature at which the reaction would be spontaneous.

Find out the value of the equilibrium constant for the following reaction at 298 K, \[\ce{2NH3_{(g)} + CO2_{(g)} ⇌ NH2CONH2_{(aq)} + H2O_{(l)}}\] Standard Gibbs energy change, `∆"G"_"r"^0` at the given temperature is –13.6 kJ mol⁻¹.

A gas mixture of 3.67 lit of ethylene and methane on complete combustion at 25°C and at 1 atm pressure produce 6.11 lit of carbon dioxide. Find out the amount of heat evolved in kJ, during this combustion. (ΔH_C(CH₄)) = − 890 kJ mol⁻¹ and (ΔH_C(C₂H₄)) = − 1423 kJ mol⁻¹