ऐसा ऊष्मागतिक निकाय (thermodynamic system) जिसमें निकाय और परिवेश के बीच पदार्थ का कोई आदान-प्रदान नहीं होता, लेकिन ऊर्जा का आदान-प्रदान संभव होता है, कहलाता है:

Consider the following reaction: 2A (g) + B (g) → 2D (g) ΔU⊖ = -10 kJ mol-1 and ΔS⊖ = -44 J K-1 at 298 K. Identify the correct option with ΔG⊖ for the reaction and spontaneity of the reaction at 298 K. (Given: R = 8.314 J mol-1 K-1)

At a certain temperature, T (K), during a process, 500 J is absorbed by the system and work of 200 J is done by the system. Then change in internal energy of the system is: