Preview - Energy In Chemical Reactions

An Introduction to Calorimetry

Because the energy transfer involved in both breaking and making bonds involves heat, or thermal energy, we can employ a method called calorimetry to measure the heat transfer. Calorimetry is the science of measuring heat. In aqueous solutions, the energy is transferred to or taken away from the water, therefore, the thermal energy transferred may be calculated using the change in temperature of the water itself.

A calorimeter can be used to measure the amount of thermal energy transferred when bonds are broken or formed. A calorimeter will consist of a container with a cover, and a thermometer or temperature probe. The ideal calorimeter (for our purposes) must prevent the transfer of thermal energy between the calorimeter's container and its environment. This allows for an accurate determination of the thermal energy that has either been transferred to or from the water within the calorimeter.

Questions

Please answer the questions below.

Describe how you expect the temperature in a calorimeter to change when an exothermic reaction occurs inside the vessel.

How might the temperature change measured in question 1.1 be affected if thermal energy is lost from the calorimeter itself? Be specific and indicate if the temperature change measured would be greater or less than the one measured where no thermal energy is lost.

How would the temperature change measured in an endothermic reaction be affected if thermal energy is lost from the calorimeter itself? Again, be specific and indicate if the temperature change measured would be greater or less than the one measured where no thermal energy is lost.

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.