Physical changes that involve liquids and aqueous solutions can be studied using a polystyrene calorimeter like the one shown in Figure 1. Such materials can be applied to practical thermochemical systems. For example, when athletes are injured, they may immediately hold an ‘instant cold pack’ against the injury; and over time, the athlete may apply ‘instant hot pack’ to help recover. The medical hot/cold pack operates on the principle that certain salts dissolve endothermically in water, while others dissolve exothermically. The amount of heat per unit mass involved in the dissolving of a compound is a characteristic property of that substance. It is called the enthalpy of solution. The purpose of this experiment is to use calorimetry to determine the enthalpy of solution of an unknown salt, and then to use that value to identify the salt in a medical hot/cold pack, from a list of possible candidates.
Related Resources:
SPLISH, SPLASH, KERPLUNK!
Categories: Lab/Student Activity
The students and teacher will go on a walk around the schoolyard/community to collect a variety of natural objects. A further collection of items from the classroom will augment this. The sorting... read more
The Ball Bearing Bounce
Categories: Lab/Student Activity
This was an exciting activity to undertake as the students did the calculations first, then we headed down to the cafeteria to try the equipment out and see if our calculations were correct. Kids... read more
Life in Space
Categories: Lab/Student Activity, Lesson Plan, Unit Plan
Note: This resource is part of the STAO Grade Six Space Unit User Guide. Click here to access the parent resource. Life in Space Unit Curriculum and Assessment... read more