3. In the next unit we will be discussing reactions that are reversible, and can go in either the forward or reverse directions. For example, hydrogen gas and oxygen gas react to form water, but water can also be broken down into hydrogen and oxygen gas. We typically write a reaction that can be reversed this way, using the double arrow symbol 2H2+O22H2O This reaction is exothermic in the forward direction: 2H2+O22H2O+285kJ but endothermic in the reverse direction: 2H2O+285kJ2H2+O2 Consider a general reversible reaction such as: A+BC+D Given the following potential energy diagram for this reaction, determine and Ea for both the forward and reverse directions. Is the forward reaction endothermic or exothermic