I found an exercise in Physical Chemistry by Atkins et al, 8th edition, page 235 that I found confusing. The question is as follows.
"7.2(b) Molecular bromine is 24 per cent dissociated at 1600 K and 1.00 bar in the equilibrium Br2(g) ⇌ 2 Br(g). Calculate (a) K at 25°C, (b) ΔrG°, (c) K at 2000°C given that ΔrH° = +112 kJ.mol^(−1) over the temperature range."
I initially assumed that to answer (b), the temperature plugged to the equation ΔrG °= -RT.ln(K) is 298.15 K since it's mentioned that the reaction Gibbs energy is standard. However, when I checked my answer with the students' solutions manual, the author of the manual plugged in 1600 K as the temperature for the solution of (b). Who is correct and why? If the solutions manual author is the correct one here, why is there no agreement for a temperature in the context of "standard Gibbs energy?"
Thanks in advance for you who answer or inform if there has been any similar questions to mine in the forum since I haven't found one as I typed this.
Edit (last done on 9.51 PM UTC+7, 8th May 2022): @orthocresol has linked a question different from mine in the sense that what was asked circa 6 years ago was different than what I asked here; however, the answer to one of the linked questions is relevant to my question.