19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25 °C increases the temperature of 18.94 kg of water by 0.632 °C. If the specific heat of water at 25 °C is 0.998 cal/g-deg, the value o…
The following two reactions are known Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g); ∆H = –26.8 kJ FeO(s) + CO(g) → Fe(s) + CO₂(g); ∆H = – 16.5 kJ The value of ∆H for the following reaction Fe₂O₃(s) + CO(g) → 2FeO(s) + CO₂(g) …
Three thermochemical equations are given below: (i) C(graphite) + O₂(g) → CO₂(g); ∆rH° = x kJ mol–1 (ii) C(graphite) + ½O₂(g) → CO(g); ∆rH° = y kJ mol–1 (iii) CO(g) + ½O₂(g) → CO₂(g); ∆rH° = z kJ mol–1 Based on the ab…
When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0°C and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed. The amount of heat released from this combust…
The heat of combustion of carbon to CO₂ is –393.5 kJ/mol. The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is (2015)
For a sample of perfect gas when its pressure is changed isothermally from pi to pf, the entropy change is given by. (NEET-II 2016)
For a given reaction, ∆H = 35.5 kJ mol–1 and ∆S = 83.6 J K–1 mol–1. The reaction is spontaneous at (Assume that ∆H and ∆S do not vary with temperature.) (NEET 2017)
The bond dissociation energies of X2, Y₂ and XY are in the ratio of 1 : 0.5 : 1. ∆H for the formation of XY is – 200 kJ mol–1. The bond dissociation energy of X2 will be (NEET 2018)
An ideal gas expands isothermally from 10–3 m3 to 10–2 m3 at 300 K against a constant pressure of 105 N m–2. The work done on the gas is (Odisha NEET 2019)
In which case change in entropy is negative? (NEET 2019)
1 mole of an ideal gas expands isothermally reversibly from 2 litre to 4 litre and 3 moles of the same gas expands from 2 litre to x litre and doing same work, what is ‘x’?
A liquid which is confined inside an adiabatic piston is suddenly taken from state 1 to state 2 by a single stage process. If the piston comes to rest at point 2 as shown. Then the enthalpy change for the process will…
If one monoatomic gas is expanded adiabatically from 2L to 10L at 1 atm external pressure then the value of U (in atm L) is
The magnitudes of enthalpy changes for irreversible adiabatic expansion of a gas from 1L to 2L is H₁ and for reversible adiabatic expansion for the same expansion is H₂. Then
Consider the reaction below at 298 K: C (graphite) + 2H₂ (g) → CH₄ (g) →fHº (kJ/mol) – 74.9 S₀ m(J/K/mol + 5.6 + 130.7 Which statement below is correct ?
What is the entropy change in 2 mol N₂, when its temperature is taken from 400 K to 800 K. at constant pressure?
B. P G T 2. T C. P H S 3. -S D. H T P 4. P 5. V
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: For an isolated system, q is zero. Reason: In an isolated system, change in U and V is zero.
Assertion: Addition of Q and w gives ΔU. Reason: Addition of two path functions cannot give state function.
Assertion: Entropy of system increases for a spontaneous reaction. Reason: Enthalpy of reaction always not decreases for spontaneous reaction.
Find r S at 320 K for the reaction is:
Which of the following is a state function?
Thermodynamics deals with
Which of the following is true about isolated system?