Thread: Endothermic reaction possiblities

For a school project, I need to create a reaction to reduce the temperature of an object.
The only liquid resources I have a Water and Vinegar. I also may use up to 10 volts of electricity. The object who's temperature could be anything. I also need this to trigger some other kind of action after the object is chilled. Suggestions???

Evaporation.


Fan.


Details for you to work out.

Water + vinegar would seem to quite a reasonable electrical conductor. Anything you can do with a conductive aqueous solution and electricity?

Get some ammonium chloride, or ammonium nitrate, or potassium chloride, put it in the water, tada!

A fan and evaporation might work

I can't think of anything directly applying electricity to an aqueous solution seeing as using electricity is usually applying heat through conductivity

your chlorides and nitrates in some cases can be explosive so I don't really know how much I can do with those...

The object to be cooled could be a thermostat and the battery could be the 9v battery in your voltmeter, or you could have a battery light a light or something through the thermostat. That would take care of the triggering action part. For the reaction, I don't know. Do an internet search on endothermic reaction.

What about a solid-solid reaction? Why not mix hydrated baruim hydroxide with ammonium chloride to produce a liquid (temp goes down around to -20 degrees) which can then be used to freeze the water.

Originally Posted by Kid-Delta

I can't think of anything directly applying electricity to an aqueous solution seeing as using electricity is usually applying heat through conductivity

Hint: electrolysis is endothermic under certain conditions.

Originally Posted by Bunbury

Originally Posted by Kid-Delta

I can't think of anything directly applying electricity to an aqueous solution seeing as using electricity is usually applying heat through conductivity

Hint: electrolysis is endothermic under certain conditions.

Yes I agree, a lot of the posters have come up with some elaborate chemicals which I doubt your chem lab will stock.

try these three scenarious (at home)

9 volt battery, 1 anode & 1 cathode.
mix water and vinegar 50/50
place thermometer inside the solution
connect anode & cathode up to battery and run a current through, give it a little while and see if the temperature is reduced; also record the length of time it takes for the solution to reduce in temperature. plot these on a graph, with half degrees on the vertical exis and time (every 30 seconds) along the horizontal axis. (you may adjust the scale of your graph to fit your results0

also try a 70/30 mix vinegar/water
and a 30/70 mix vinegar/water

plot these graphs too to see if adjusting the mixture makes any difference.

do each of these experiments twice and compare your results to obtain an average result from each.

Use a brand new 9v battery on each experiment.

Originally Posted by Kid-Delta

For a school project, I need to create a reaction to reduce the temperature of an object.
The only liquid resources I have a Water and Vinegar. I also may use up to 10 volts of electricity. The object who's temperature could be anything. I also need this to trigger some other kind of action after the object is chilled. Suggestions???

You can use up to 10 volts of magnetism but you can send how many electrons you want.
In other word transform 230 v to 10 v and increase the ampear, just to piss of your teatcher:P