Designing a Safe, Effective
Hand Warmer
There have been some bitterly cold days this past
winter, agreed? Wouldn’t it be nice to have a small
packet that you could carry in your mittens and have
access to warmth whenever you needed it? There are
commercial hand warmers available, but your
challenge is to design a better one. From your study of
thermochemistry and calorimetry, you have learned
that the very act of dissolving ionic solids in water can
lead to a change in temperature. Sometimes the
temperature increases, sometimes the temperature
decreases. At the following web site, you can perform virtual tests that will help you in your quest.
Virtual calorimetry lab
Some questions to consider:
Which compound produces the greatest temperature change? Remember what you need for a ‘fair’
test of each compound.
How much of a temperature change is needed? What if the temperature changed enough to boil water,
would that compound be a good candidate to put in your mittens?
How much does each compound cost per gram? You might have a great candidate in terms of
producing the largest temperature change, but if it’s a very expensive product, who will buy it?
Ideally, you want to carry this around with you, either in your backpack, pocket or handbag, so you don’t
want to lug around a toxic substance. Therefore, you need to check out the MSDS (GHS) information for
each compound.
Are there any environmental concerns about the disposal of the compounds?
For the trials, you are limited to the compounds listed at the site for the virtual lab. Can you make use
of tables of thermodynamic data to determine better candidates for your hand warmer?
You will report your findings via a Google document. Your report needs to contain the following information:
Hypothesis (you will need to do some research before you ‘run’ the tests to make a testable hypothesis).
Background/theory: Explain what happens when ionic compounds are dissolved in water and why some
produce greater temperature changes than others.
Since this is a virtual lab, there will be no materials list, but you do need to include any web sites you
accessed for MSDS information.
Data table: This needs to contain all compounds tested, amounts tested, and temperature change for
those masses.
Analysis: Discuss your findings about the MSDS (GHS) and cost of each compound.
Conclusion: Which compound did you determine would be the best candidate for an effective hand
warmer? Provide all the reasons you think that compound would be the best, and also discuss the mass
amounts that would be most effective. If you conclude that a compound that is not on the virtual lab
tested list would make a more effective hand warmer, explain your reasoning in detail.
Because this report will be a Google doc, you can add in any extra pictures, cartoons, animations, etc., that you
think will aid in understanding the thermochemistry involved. You may receive up to 10 extra credit points for
designing a package for your product and a memorable brand name (the designed package should be a drawing,
not something you actually make). Since I can Google almost as well as you, the following names are probably
copyrighted and not available for your extra credit desires: Hot Hands, Heat Wave, Hot Snapz, Heat Treat, Heat
Factory, Wonder Warmers, Hotties, Heat Works, Hot Rods, or Mega Warmer. Whew!
As in the last Google doc you created, include all referenced material in a comment instead of at the end of the
report as you would in MLA or APA style.
Due date: April 16