The reaction of gaseous H2 and liquid Br2 to give gaseous HBr has ΔH = -17.4 kcal/mol (-72.8 kJ/mol) and ΔS = 27.2 (cal/mol⋅K) (114 J/(mol⋅K)). What is the value of ΔG (in kcal and kJ) for the reaction at 297 K ?

Answer 1

dG = dH - TdS
Isn't this just a plug and chug? Don't forget that dS in in cal while dH is in kcal.