The work done when 1 mole of gas expands reversibly and isothermally from a pressure of 5 atm to 1 atm at 300 K is: ​
(Given log 5 = 0.6989 and R = 8.314 J K-1 mol-1)
1. zero J
2. 150 J
3. +4014.6 J
4.-4014.6 J

Subtopic:  First Law of Thermodynamics |
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Level 2: 60%+
NEET - 2022
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One mole of an ideal gas at 300 K is expanded isothermally from 1 L to 10 L volume. \(\Delta U\) for this process is:
(Use R = 8.314 J K–1 mol–1)
1. 1260 J 2. 2520 J
3. 5040 J 4. 0 J
Subtopic:  First Law of Thermodynamics |
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Level 1: 80%+
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Which p-V curve among the following depicts the highest amount of work done?
 
1. 2.
3. 4.
Subtopic:  2nd & 3rd Law of Thermodynamics |
 86%
Level 1: 80%+
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Tin is obtained from cassiterite by reduction with coke. Use the data given below to determine the minimum temperature (in K) at which the reduction of cassiterite by coke would take place at -
\(298 \mathrm{~K}: \Delta_{f} H^{\circ}\left[\mathrm{SnO}_{2}(s)\right]=-581.0 kJ \mathrm{~mol}^{-1}\)
\(\begin{aligned} &\Delta_{f} H^{\circ}\left[\left(CO_{2}\right)(g)\right]=-394.0 k J mol^{-1} \\ &S^{\circ}\left[\mathrm{SnO}_{2}(s)\right]=56.0 JK^{-1} \mathrm{~mol}^{-1} \\ &S^{\circ}[\operatorname{Sn}(s)]=52.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1} \\ &S^{\circ}[C(s)]=6.0 \mathrm{JK}^{-1} \mathrm{~mol}^{-1} \\ &S^{\circ}\left[\mathrm{CO}_{2}(g)\right]=210.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1} \end{aligned}\)
(Assume that the enthalpies and the entropies are temperature independent)
1. 298 K
2. 450 K
3. 935K
4. 900 K
Subtopic:  Spontaneity & Entropy |
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One mole of an ideal gas at 900 K undergoes two reversible processes, I followed by II, as shown below. If the work done by the gas in the two processes is same, the value of \(ln {V_3 \over V_2}\) is:

(U: internal energy, S: entropy, p: pressure, V: volume, R: gas constant)
(Given : molar heat capacity at constant volume, \(C_{v,m}\) of the gas is \({ 5 \over 2 }R\))
1. 5
2. 10
3. 0.1
4. 0.5
Subtopic:  First Law of Thermodynamics |
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Level 3: 35%-60%
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What is the correct relationship between changes in enthalpy and internal energy within the following options?
1. \(\mathrm{\Delta {H}+\Delta {U}=\Delta {nR}} \)
2. \(\mathrm{\Delta {H}=\Delta {U -\Delta n_gRT}}\)
3. \(\mathrm{\Delta {H}=\Delta {U+\Delta n_gRT }}\)
4. \(\mathrm{\Delta {H} -\Delta {U=-\Delta n_gRT}}\)
Subtopic:  Enthalpy & Internal energy |
 83%
Level 1: 80%+
NEET - 2023
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Consider the following reaction:
\(\mathrm{2H_2(g) + O_2(g) \rightarrow 2H_2O(g); ~\Delta_rH^\circ = -483.64~ kJ }\)

What is the enthalpy change (in KJ) for the decomposition of one mole of water?
1. 120.9 2. 241.82
3. 18 4. 100
Subtopic:  Thermochemistry |
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If it is discovered that a certain non-spontaneous reaction becomes spontaneous if the temperature is lowered, then which of the following must be true:
1. ∆S is negative and ∆H is positive
2. ∆S is negative and ∆H is negative
3. ∆S is positive and ∆H is positive
4. ∆S is positive and ∆H is negative
Subtopic:  Spontaneity & Entropy |
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The specific heat of tungsten is 0.03 cal/g-°C. If a 50-gram sample of tungsten absorbs 100 calories of heat, the change in temperature of the sample will be:

1. 76 °C
2. 55 °C
3. 67 °C
4. 62 °C
Subtopic:  Cp & Cv |
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Level 1: 80%+
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Calculate the change in internal energy when 1 mole of water vapor, treated as an ideal gas, at 100°C and 1 bar pressure is transformed into ice at 0°C. 
(The enthalpy of fusion of ice = 6.00 kJ mol
-1 , heat capacity of water = 4.2 J/g°C)

1. 13.56 kJ mol-1

2. –12.16 kJ mol-1

3. –13.56 kJ mol-1

4. 12.16 kJ mol-1

Subtopic:  Thermochemistry |
 52%
Level 3: 35%-60%
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