How to find exact 95 deg centigrade without using any thermometer ?

Question

Hey this is tricky, well need to do it. I need to find when my water in a heating pot reaches exact 95 deg c without using any form of thermometer

Answer 1

They make special "crayons" for industrial purposes; the markings melt at specified temperatures (a cheap test to verify that something being heated to specifed temperature actually made it there). They probably make one for 95 C. Just mark on the pot (away from the heat source).

Maybe track the density of the water. Find something that doesn't dissolve/melt in 95 C water, that is the same density at water at 95 C. Heat until it becomes neutral boyancy. (Maybe some kind of plastic?)

Related to above; monitor the thermal expansion by having markings on the side of the pot (you would need to calibrate the pot beforehand). This would be affected by evaporation of water so not as good as above method.

Find out what pressure water boils at 95 C. Keep your pot at this pressure by covering and using a vacuum pump/valves, regulator; when it boils it's at 95 C (will be slightly below atmospheric) [you didn't say you couldn't use a pressure gauge/vacuumpump].

Water will form azeotropes with various materials that boil at 95 C such as chloral, cyclohexanone, isopropyl benzene, and nonane. But you wouldn't be able to cook with it!

I think the second method is most likely to be useful.

Answer 2

Mix some boiling water with some room-temperature water and use specific heats to make sure the resulting solution is exactly 95 degrees celsius.

This whole thing sounds so contrived. Your teacher is a douche.

Answer 3

the boiling point of water is 100 deg centigrade, at exactly 95 deg, the water is at its popping motion then it will create vapors..

Answer 4

converting from celsius to farenheit the equation is as follows

The Temperature in Farenheit = 9/5 (The temperature in Celsius) + 32

95 in C 203 F