NEET Chemistry — Thermodynamics

Q1. For a reversible isothermal expansion of an ideal gas, the work done is given by:

• A. \(nRT \ln(V_2/V_1)\)
• B. \(-nRT \ln(V_2/V_1)\)
• C. \(nRT\)
• D. Zero

Q2. Calculate \( \Delta S_{sys} \) for the condensation of 1 mol of ethanol at 351 K. (\( \Delta H_{vap} = 38.6 \, \text{kJ/mol} \))

• A. 38.6 J/K·mol
• B. 110.0 J/K·mol
• C. -110.0 J/K·mol
• D. -351.0 J/K·mol

Q3. For an ideal gas undergoing adiabatic expansion from 2 L to 4 L at 400 K (\( \gamma = 1.67 \)), what is the final temperature?

• A. 200 K
• B. 252 K
• C. 315 K
• D. 400 K

Q4. Using bond enthalpies (\(C-H = 413 \, \text{kJ/mol}\), \(Cl-Cl = 243 \, \text{kJ/mol}\), \(C-Cl = 328 \, \text{kJ/mol}\), \(H-Cl = 431 \, \text{kJ/mol}\)), calculate \(\Delta H\) for \(CH_4(g) + Cl_2(g) \rightarrow CH_3Cl(g) + HCl(g)\).

Q5. Calculate the work done when 1 mol of an ideal gas (\( \gamma = 1.67 \)) is compressed adiabatically from 20 L to 4 L at 300 K. (\( R = 8.314 \, \text{J/mol·K} \))

• A. 0 J
• B. -6068.3 J
• C. 6068.3 J
• D. 3034.2 J