Life Heat
We got the idea for our project by thinking about how helpful it would be to have a lifejacket that would self-heat with simple materials in order to prevent hypothermia — a dangerous health condition caused by prolonged exposures to very cold temperatures. We became interested in this topic because we both love sailing, and of course lifejackets are critical. Hypothermia is very real threat to anyone who is around water, so we wanted to do an experiment that would help us develop a self-heating life jacket.
Calcium chloride is a chemical used in a variety of ways, such as on ice for roads, etc, and it creates an exothermic reaction that generates heat when mixed with water. When the naturally occurring salt ions in the water are mixed with calcium chloride the water molecules’ electrical charge becomes unevenly dispersed resulting in the formation of new hydrogen bonds. This exothermic reaction produces heat. The purpose of this experiment was to determine the temperature and duration of the exothermic reaction when calcium chloride is mixed with water of varying salinities (salt water, estuary water and freshwater) to see if this reaction could be harnessed to prevent hypothermia in aquatic environments that have different salinity levels.
This experiment was developed to refine our ideas on what is possible to develop a lifejacket to prevent hypothermia that works in both lakes and oceans, we were hoping to learn if the exothermic reaction would give off enough heat, and if the reaction might be different in lakes or oceans.
The steps we took for our project were to first research as much as we could about calcium chloride and exothermic reactions with water. We then collected water samples from nearby locations around Victoria, B.C., two saltwater water samples, a freshwater sample and a brackish water sample from an estuary where a river meets the ocean. We mixed the same amount of water from each sample with the same amount of calcium chloride and measured the temperature before and after. The results show that even though there were small differences in the temperatures generated by the exothermic reaction for each sample, the heat generated was almost 40 degrees Celsius for all the samples. When freshwater, estuary water and ocean water are each mixed with calcium chloride, an exothermic reaction lasting an average of two hours results. Our experiment confirms that calcium chloride, a widely available chemical, could potentially be used in lifejackets in these aquatic environments to prevent hypothermia.
