Science Common Sense


1727 - What factors affect the heat of reaction?

There are several factors that affect the heat of reaction:

  1. Concentration of reactants: If there's more of the reactants, there will be more collisions, which can make the reaction give off more heat.
  2. Surface area of reactants: If the reactants have a bigger surface area, there's more chance for collisions, making the reaction hotter.
  3. Temperature: Higher temperatures give reactants more energy, making them more likely to collide and react, releasing heat.
  4. Pressure: Higher pressure can also increase the chances of collisions, making the reaction hotter.
  5. Catalysts: Some substances, called catalysts, can help speed up reactions or make them give off more heat, but they don't get used up in the reaction.
  6. Type of reaction: Some reactions naturally give off more heat than others.