Question

Explain what happens in an endothermic reaction and what happens in an exothermic reaction. How can we identify whether a reaction is endothermic or exothermic?

Answer 1

A calorimeter is a device that carefully measures the temperature of an isolated system both before and after a reaction takes place. The change in temperature tells us whether thermal energy was absorbed or released, and how much. This gives us important information about the products, reactants and the nature of the reaction.Calorimetry experiments measure the amount of thermal energy gained or lost during a reaction by measuring the temperature before and after. Based on the temperature change, the masses of the substances and equipment, and another property called the heat capacity (which may be different for each component), one calculates the change in thermal energy that occurred during the reaction. If the change is positive, then thermal energy was released, and the process is exothermic. If the change is negative, then thermal energy was absorbed, and the process is endothermicA calorimeter is a closed, insulated container in which the chemical reaction proceeds in an isolated environment. The calorimeter also includes a way to measure the temperature before and after the reaction. There are two main types of calorimeters: constant pressure calorimeters and constant volume calorimeters. A Styrofoam cup with a lid and a thermometer makes a basic constant pressure calorimeter useful for home experiments. The reaction is always at atmospheric pressure. A constant volume bomb calorimeter is more complicated. The reaction takes place in a thick-walled, sealed container that is immersed in an insulated water bath.