Is the temperature of a reaction related to the concentration of reactants? 

Students make predictions, collect and interpret data and make conclusions during the laboratory activity.  Graphs are java-based so no other software is necessary.  The activity is customizable on the ITSI-SU (free) web site.

Sensor needed:  Temperature probe

Time needed:  2 class periods

In this activity the temperature of a reaction is monitored for different concentrations of reactants.

Does change in concentration change the amount of heat released in a chemical reaction?

When yeast is added to a hydrogen peroxide (HOOH) solution, bubbles start to form and the solution foams up. Do you think this is an endothermic (heat-absorbing) reaction or an exothermic (heat-producing) reaction?

When baking soda is added to vinegar, bubbles form and the solution fizzes violently. Do you think this is an endothermic or an exothermic reaction?

If the products of a reaction contain less chemical energy than the reactants, is the reaction endothermic or exothermic? Why?

If the products of a reaction contain more chemical energy than the reactants, is the reaction endothermic or exothermic? Why?

Does change in concentration change the amount of heat released in a chemical reaction?

See the link below for the interactive resource.  After creating a free account, you will have access to all ITSI-SU Math and Science interactive resource and lessons.

Chemical Reactions:  Heat Changes SAS/ITSI-SU 2040

The Concord Consortium: http://www.concord.org/

reactions reaction concentration heat endothermic exothermic energy experiment laboratory graph data ITSI-SU chemistry itsi concord