19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
In which case change in entropy is negative? (NEET 2019)
Which thermodynamic parameter is not a state function?
A system undergoes a 3-step process. In step 1, 25 J of work is done by the system as its internal energy (U) decreases by 50 J. In step 2, w = -15J and q = +40J. In step 3 at constant volume, the system gives off 50 …
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…
A diatomic gas at pressure P, compressed adiabatically to half of its volume, what is the final pressure?
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
For the reaction of one mole of zinc dust with one mole of sulphuric acid in a bomb calorimeter, U and w correspond to
In an isobaric process, when temperature changes from 1T to T , S is equal to
For which of the following cases H S T ?
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: The extensive properties of a single pure substance will not only depend upon the number of moles of the substance present but also on any two of the three variables. Reason: Any extensive property if expre…
Assertion: For an isolated system, q is zero. Reason: In an isolated system, change in U and V is zero.
0.1 M NaCl and 0.05 M BaC₁₂ solutions are separated by a semipermeable membrane in a container. For this system, choose the correct answer. (AMU 2010)
The boiling point of water is 1000C. What will be the boiling point of an aqueous solution containing 0.6 g of urea (molar mass = 60) in 100 of water? b k for water 0.52 K / m (RPMT 2010) (a) o 100.052 C (b) o 101.052…
The relative lowering of vapour pressure is equal to the ratio between the number of (BVP 2010)
A solution of sucrose (molar mass = 342g mol -l) has been prepared by dissolving 68.5g of sucrose in 1000g of water. The freezing point of the solution obtained will be (Kf for water = 1.86 K Kg mol-l) (AFMC 2010) (a)…
A solution contains non-volatile solute of molecular mass M2. Which of the following can be used to calculate the molecular mass of solute in terms of osmotic pressure? (Punjab PMET 2007) (a) m M VRT (b) m RT M V (c) …
If the elevation in boiling point of a solution of 10 g of solute (molecular weight = 100) in 100 g of water is b T , the ebulliscopic constant of water is (Manipal 2010)
The empirical formula of a non-electrolyte is CH₂O. A solution containing 3 g of the compound exerts the same osmotic pressure as that of 0.05 M glucose solution. The molecular formula of the compound is (KCET 2011)
If is degree of dissociation of Na₂SO₄, the van’t Hoff’s factor, i, used for calculating the molar mass is
If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water ( Tf), when 0.01 mole of sodium sulphate is dissolved in 1 kg of water, …
0.2 molal acid HX ionises 20%. Kf for acid is 1.86 molality–1. Freezing point is
Van’t Hoff factor of Ca (NO₃)₂ is
Which of the following aqueous solutions has the highest boiling point?
0.01 M solution each of urea, common salt and Na₂SO₄ are taken, the ratio of depression of freezing point is