For an ideal gas four processes are marked as 1, 2, 3 and 4 on P-V diagram as shown in figure. The amount of heat supplied to the gas in the process 1, 2, 3 and 4 are Q1, Q2, Q3 and Q4 repectively, then correct order of heat supplied to the gas is

[AB is process-1, AC is process-2, AD is adiabatic process-3 and AE is process-4]

1. Q1>Q2>Q3>Q4

2. Q1>Q2>Q4>Q3

3.  Q1>Q4>Q2>Q4

4. Q1<Q2<Q3<Q4

Subtopic:  First Law of Thermodynamics |
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NEET 2023 - Target Batch - Aryan Raj Singh
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The latent heat of vapourisation of water at 25C is 10.5 kcal mol-1 and the standard heat of formation of liquid water is -68.3 kcal. The enthalpy change of the reaction

H2g+1/2O2gH2Og is therefore,

1. -57.8 kcal

2. -78.8 kcal

3. 78.8 kcal

4. -47.3 kcal

Subtopic:  Enthalpy & Internal energy |
 60%
From NCERT
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NEET 2023 - Target Batch - Aryan Raj Singh
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Which of the following thermodynamic quantities is an outcome of the second law of thermodynamics?

1. Work

2. Enthalpy

3. Internal energy

4. Entropy

Subtopic:  Spontaneity & Entropy |
 76%
From NCERT
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NEET 2023 - Target Batch - Aryan Raj Singh
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To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

From the following data of H, of the following reactions,

Cs+12O2COg    ;H=-110 kJ
Cs+H2OCOg+H2g  ;H=132 kJ

What is the mole composition of the mixture of steam and oxygen on being passed over coke at 1273 K, keeping temperature constant.

1. 0.5 : 1

2. 0.6 : 1

3. 0.8 : 1

4. 1 : 1

Subtopic:  Enthalpy & Internal energy |
 51%
From NCERT
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State which of the following statements is true ?

1. First law of thermodynamics is not adequate in predicting the direction of the process.

2. In an exothermic reaction, the total enthalpy of the products is greater than that of reactants.

3. The standard enthalpy of diamond is zero at 298 K and 1 atm pressure.

4. It is possible to calculate the value of H for the reaction H2g+Br2l2HBrg from the bond enthalpy data.

Subtopic:  First Law of Thermodynamics |
 51%
From NCERT
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The intermediate SiH2 is formed in the thermal decomposition of silicon hydrides. Calculate Hf of SiH2 given the following reactions

Si2H6g+H2g2SiH4g; H=-11.7 kJ/mol
SiH4gSiH2g+H2g; H=+239.7 kJ/mol
Hf, Si2H6g=+80.3 kJ mol-1

1. 353 kJ/mol

2. 321 kJ/mol

3. 198 kJ/mol

4. 274 kJ/mol

Subtopic:  Thermochemistry |
 53%
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A certain vessel X has water and nitrogen gas at a total pressure of 2 atm. and 300 K. All the contents of the vessel are transferred to another vessel Y having half the capacity of the vessel X. The pressiure of N2 in this vessel was 3.8 atm. at 300 K. The vessel Y is heated to 320 K and the total pressure observed was 4.32 atm. Calculate the enthalpy of vapourisation of water assuming it to be independent of temperature. Also assume the volume occupied by the gases in a vessel is equal to the volume of the vessel.

1. 39.637 kJ mol-1

2. 19.531 kJ mol-1

3. 396.37 kJ mol-1

4. 3.9127 kJ mol-1

Subtopic:  Enthalpy & Internal energy |
From NCERT
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For a reaction, A+BAB, cP is given by the equation 40+5×10-3 T JK4 in the temperature range 300-600 K. The enthalpy of the reaction at 300 K is -25.0 KJ. Calculate the enthalpy of the reaction at 450 K.

1. -10.12 kJ

2. -28.32 kJ

3. -18.72 kJ

4. -8.21 kJ

Subtopic:  Enthalpy & Internal energy |
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The heat of combustion of ethylene at 17C and at constant volume is -332.19 kcals. What is the value at constant pressure, given that water is in liquid state ?

1. -131.25 k cals

2. -412.23 k cals

3. -534.12 k cals

4. -333.35 k cals

Subtopic:  Enthalpy & Internal energy |
 58%
From NCERT
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The enthalpies of the following reactions are shown alongwith.

12H2g+12O2gOHg ; H=42.09 kJ mol-1
H2g2Hg;                      H=435.89 kJ mol-1
O2g2Og;                      H=495.05 kJ mol-1

Calculate the O-H bond energies for the hydroxyl radical.

1. 223.18 kJ mol-1

2. 423.38 kJ mol-1

3. 513.28 kJ mol-1

4. 113.38 kJ mol-1

Subtopic:  Thermochemistry |
 77%
From NCERT
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