In the process of photosynthesis, when a glucose molecule is formed, THE HEAT CONTENT OF THE REACTION INCREASES, THUS, THE VALUE OF Q IS POSITIVE.
There are two types of chemical reaction, these are exothermic and endothermic reaction. Exothermic reactions are those reactions that gives off heat when they are occurring while endothermic reactions are those reactions that absorb heat from their environment during the course of reaction. Photosynthesis is an endothermic reactions; it absorbs energy from the environment when it is occurring, thus, the heat content of the product is always more than that of the reactants. The heat content of compounds are represented by letter q. For photosynthesis, q is positive, because there is an increase in the heat content of the product [glucose] formed.
