Thermodynamics Questions

A solution of 500 ml of 0.2 M KOH and 500 ml of 0.2 M HCl is mixed and stirred; the rise in temperature is T₁. The experiment is repeated using 250 ml of each solution, the temperature raised is T₂. Which of the following is true -

The heat of neutralization of HCN by NaOH is 13.3 kJ/mol, the energy of dissociation of HCN is -

The heats of neutralisation of four acids a, b, c and d when neutralised against a common strong base are 13.7, 9.4, 11.2 and 12.4 kcal respectively. The weakest acid among these is

The value of ΔHsol of BaCl₂(s) and BaCl₂·2H₂O(s) are −a kJ and b kJ respectively. The value of ΔHHydration of BaCl₂(s) is-

The lattice energy of solid NaCl is 180 kcal mol⁻¹. The dissolution of the solid in water in the form of ions is endothermic to the extent of 1 kcal mol⁻¹. If the hydration energies of Na⁺ and Cl⁻ ions are in the ratio 6 : 5, what is the enthalpy of

HA + OH⁻ → H₂O + A⁻ + q₁ kJ H⁺ + OH⁻ → H₂O + q₂ kJ The enthalpy of dissociation of HA is

The enthalpy of combustion of a substance -

Enthalpy of formation of compound is -

For the process, melting of ice at 260 K the ΔH is -

The enthalpies of all elements in their standard states are -

From the following data, the heat of formation of Ca(OH)₂(s) at 18°C is ______ kcal:

Ammonium nitrate can decompose with explosion: NH₄NO₃(s) → N₂O(g) + 2H₂O ; ΔH = −37.0 kJ mol⁻¹ Calculate the heat produced when 2.50 g NH₄NO₃ decomposes -

In the combustion of 4 g of CH₄, 2.5 kcal of heat is liberated. The heat of combustion of CH₄ is -

One litre-atmosphere is approximately equal to-

For a chemical reaction, 2A₂(g) + 5B₂(g) → 2A₂B₅(g), at 27°C the difference between ΔH and ΔE is X. Then the ratio X/R -

Difference between ΔH and ΔE for the combustion of liquid benzene at 27°C is -

A state function is that -

Which among the following is not a state function -

Select the correct order in the following:

ΔH for CaCO₃(s) → CaO(s) + CO₂(g) is 176 kJ mol⁻¹ at 1240 K. The ΔU for the change is equal to:

For hypothetical reaction - A(g) + B(g) → C(g) + D(g) Which of the following statements is correct -

The heat of reaction at constant volume (ΔE) and that at constant pressure (ΔH) are related as-

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

Identify the state functions among the following

Heat of reaction forC6H12O6 (s) + 6O2(g) → 6CO2 (g) + 6H2O (g)at constant pressure is –651 Kcal at 17ºC. Calculate the heat of reaction at constant volume at 17ºC

A gas absorbs 200J of heat and expands against the external pressure of 1.5 atm from a volume of 0.5 litre to 1.0 litre, Calculate the change in internal energy

The heat of dissociation of benzene in isolated gaseous atoms is 5535 kJ/mol. The bond enthalpies of C–C, C=C and C–H bonds are 347.3, 615 and 416.2 kJ respectively. Magnitude of resonance energy of benzene is :

The value of log10K for a reaction A⇌B is: (Given, ΔrH°298K = −54.07 kJ mol−1, ΔrS°298K = 10 JK−1 mol−1 and R = 8.314 JK−1 mol−1 ; 2.303 × 8.314 × 298 = 5705)

For which of the following species, standard molar enthalpy of formation at 298 K will not be zero?

Match Bonds in List-I with their bond enthalpies in List-II List-I List-II a. H—H (i) 318 kJ mol⁻¹ b. O—H (ii) 464 kJ mol⁻¹ c. H—F (iii) 435.8 kJ mol⁻¹ d. P—H (iv) 569 kJ mol⁻¹ The correct option is

The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0°C is :

An equal volume of 1M HCl and 1M H2SO4 are neutralized by 1M NaOH solution and X and Y KJ/eq. of heat liberated respectively correct relationship is:-

In which of the following cases entropy decreases?

An ideal gas expands in volume from 1 × 10–3 m3 to 1 × 10–2 m3 at 300 K against a constant pressure 1 × 10^5 Nm–2. The work done is;

Identify the correct statement regarding entropy.

A well stoppered thermos flask contains some ice cubes. This is an example of:

Calculate the work done when 1 mole of an ideal gas is compressed reversibly from 1.0 bar to 4.00 bar at constant temperature of 300 K.

The temperature of an ideal gas increases in an:

Which of the following relations are correct? A. ΔU = q + PV B. ΔG = ΔH – TΔS C. ΔS = qrev/T D. ΔH = ΔU + nRT

The hydration energies of K+ and Cl– are - x and -y kJ/mol respectively. If lattice energy of KCl is -z kJ/mol, then the heat of solution of KCl is :

Formation of ozone takes place as O2(g) + O(g) → O3(g), ΔH = –107.2 kJ Assuming O = O bond energy as 498.8 kJ mol–1, the average bond energy of ozone is;

Heat evolved in the reaction H2 + Cl2 → 2HCl is 182 kJ. Bond energies of H—H and Cl—Cl are 430 and 242 kJ mol–1 respectively. The H–Cl bond energy is :

The ∆H°f for CO2(g), CO(g) and H2O(g) are –393.5, –110.5 and –241.8 kJ mol–1 respectively the standard enthalpy change (in kJ) for the reaction CO2(g) + H2(g) → CO(g) + H2O(g) is:

Thermochemical reactions C(graphite) + 1/2 O2(g) → CO(g) ; ΔH = –110.5 kJ …(i) CO(g) + 1/2 O2(g) → CO2(g) ; ΔH = –283.2 kJ …(ii) From the above reaction, the heat of reaction for C(graphite)+O2(g) → CO2(g) will be

In an adiabatic process which of the following is true :–

∆U is always positive when;

A gas expands from a volume of 1 m3 to a volume of 2 m3 against an external pressure of 105 N m–2. The work done by the gas will be;

Lattice and hydration energies of NaCl are +777.8 kJ mol–1 and –774.1kJ mol–1 respectively. Heat of solution of NaCl will be;

Which of the following is not a state function?

∆Hneutralisation is;