anyone know how to keep a glass or container of water at constant temp of 98.6 (f) for a period of 30 min.?
452197
Drink it. Thirty minutes later, go to the bathroom.
254615
You would need to make a distiller of sorts - the sun's rays could evaporate the pure water, and you would just need to capture the water vapor - use a leaf or something similar to direct the vapor into a cup.  \n\nHere's a link on PBS Kids that explains it. Of course, on a deserted Island, you might not have plastic wrap, but you could very well improvise.
412111
Here's some ideas\n\n(1)\nMeasure the hardness and ion content of your local water supply.  You can perform precipitation experiments, measure solid residue after evaporation, and more.\n\n(2)\nSeparate the protein solids and fat from milk.  I think you can do this by adding salt to the milk.  (I've never done it, may be too easy.)\n\n(3)\nDo a project on the danger of confined spaces.  There is a really cool visual experiment that goes along with this.  If you mix vinegar and baking soda in a tall glass you will get a glass full of carbon dioxide.  Since the carbon dioxide is heavier than air, it will stay in the glass for a while (invisibly so).  You can then make a "pouring action" and pour the CO2 into a second glass, although there is no visible flow of gas.  You also need a 3rd glass that has a small, lit candle at the bottom of the glass.  You then make the same pouring action with the second glass into the third and when the CO2 displaces the oxygen and nitrogen in the third glass the candle will get snuffed out.  You can even do this experiment at home for fun!\n\n(4)\nMeasure the pH of common household materials: foods, cleaners, etc.
323207
You could test whether or not salt really does make water freeze more slowly or boil more quickly. Just get four containers of water--two for boiling and two for freezing--and a thermometer. \n\nWith one of the containers without salt, put a thermometer in it and boil and time how long it takes. Mark the boiling point temperature and time. \n\nDo the same thing but one of your containers with salt. Compare your temperatures and times.\n\nThen, you can do the same two steps with freezing with the other two containers.\n\nIf you wanted to get really crazy, you could test to see whether a lot of salt vs. a little amount of salt makes a difference. Or, if you wanted to tone it down, you could do only one--the boiling or the freezing. \n\nThis seems to me like concepts that a second grader could handle.\n\nGood luck!
757850
use multiple effect evaporator.\nhttp://www.answers.com/topic/sugar
617601
This is not as simple of a question as you have assumed.  The rate of cooling will depend on the mass of the water, that is, how much water you have.  Secondly it will depend on how well the container conducts heat.  Thirdly, what is the surface area of the container.  The greater the surface area, the faster the water will cool.  You must also consider air movement in the immediate area of the container.  If there is air movement, the cooling rate will be affected by how much air flows over the surface of the container.  Next, you must know the temperature at which the water boils.  The higher the altitude the lower the boiling point.  Finally what is the temperature and humidity in the room?
742159
So lets roll...\n\nmathematically, set it up as follows:\n\nLet x = the number of kg of water @ 82degC that must be added\n\nEnergy = m * c * T\n(m = mass, c = specific heat of water, T = tempearature)\n\nNeglecting convective and radiation heat losses:\n\n (x kg)*c*(82 C) + (0.2kg)*c*(14 C) = (x + 0.2 kg) *c*(36 C)\n\ndividing by c and re-arranging:\n\n82x + 2.8 = 36x + 7.2\n\nx = 0.096 kg
831401
Put it in hot water.\n\nTo slow the process put it in ice cold water.
1182770
Fill the bottle with water but not completely full and using a bike pump fill the bottle with air while aiming it where you want it to go; and you just keep pumping the air in until it fires.\n\nI suggest you build some sort of mount so you aren't holding the bottle when it goes off. I also suggest you try different sized bottles and different amounts of water.
563276
Drink warm baking soda water\n\n...like a tablespoon of baking soda in a teacup of water
571405
?!?!?! Make a hot bowl of boiling water then stick ur head over it 4 a few minutes!
765206
You need to get a device called a 'water rehydrator'. It essentially rehydrates powdered water. They are pretty expensive though...
461446
I found that cold water (38 degrees Fahrenheit) froze faster than hot water out of the tap (125 degrees F). I chose these two temperatures because (1) they were pretty much what the average amateur ice-cube maker would have readily available and (2) I couldn't find a mercury thermometer that went higher than 125 degrees.\n\nJearl, who is not afflicted with penny-pinching editors like some of the rest of us, was able to get his mitts on a thermocouple that could measure as high as the boiling point, 212 degrees F. He found that water heated to, say, 195 degrees would freeze three to ten minutes faster than water at 140-175 degrees. (There were differences depending on how much water was used, where the thermocouple was placed, and so on.) \n\nJearl suggested that the most likely explanation for this was evaporation: when water cools down from near boiling to the freezing point, as much as 16 percent evaporates away, compared to 7 percent for water at 160 degrees. The smaller the amount of water, of course, the faster it freezes. \n\nIn addition, the water vapor carries away a certain amount of heat. To test this theory, Jearl covered his lab beaker with Saran Wrap to prevent water vapor from escaping. The freezing rate difference was greatly diminished. Conceivably convection (motion within the water) also plays a role.\n\nFascinating as all this no doubt is, all it basically proves is that very hot water freezes more slowly than very VERY hot water. The ordinary fumbler in the fridge, on the other hand, is dealing with temps more like the ones I was measuring, in which case cold freezes faster than hot. I rest my case.
1144757
Try a cool damp cloth. Not too cold though.
698323
warm water with honey and lemon - it is natural and feels great. It also works. Tea with honey and lemon would also do the trick.
618428
Another hint.  Fill the inner one with ice and then water to help conduct heat out of the inner pitcher. Do this when both pitchers are dry in between to help keep them thermall isolated, and also to lessen the risk of cracking the outer one when you dunk it in hot water (if they are pyrex or other tempered glass, this should not be a problem anyway.) \n\nTake care not to dip them so far into the hot water that it comes in over the top of the big pitcher. Good luck!
700792
ICE..keep the ice on it for a while trust it works FAST