The reaction of gaseous H2 and liquid Br2 to give gaseous HBr has

The reaction of gaseous H2 and liquid Br2 to give gaseous HBr has ?H = -17.4 kcal/mol and ?S = 27.2 cal/(mol·K).a. Is this reaction spontaneous at all temperatures? Explain.b. What is the value of ?G for the reaction at 250 K?—my biggest issue on part b is converting to the correct units. How do I get to Joules and Joules/Kelvin from kcal/mol and cal/(mol x K)? and where/how do the units cancel?