Please help me with these Chemistry questions.

Question

1. The following reaction was used to fuel the rockets in the Apollo mission landing module. Is this reaction endothermic or exothermic? How do you know?

2.Does the graph below represent an endothermic or an exothermic reaction? How do you know? Explain.

3.What does ΔG measure? How do we use this to determine if a reaction is spontaneous or not?

Answer 1

1). The reaction is exothermic. You can tell this because the sign of the value for ∆H is negative.

2). This reaction is endothermic. You can tell because the ∆H is positive, i.e. the products have a higher value than the reactants.

3). ∆G measures the change in useful energy. If this value is negative, the reaction is spontaneous. If it is positive, the reaction is not spontaneous. If it is equal to zero, the reaction is at equilibrium.