Consider the reactions given below. On the basis of these reactions, find out which of the algebraic relations given in the options is correct: (a) C(g) + 4H(g) → CH4(g); ΔrH = x kJ mol−1 (b) C(graphite, s) + 2H2(g) → CH4(g); ΔrH = y kJ mol−1

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: