please explain the methodology
2006-07-07 06:32:47 · 3 answers · asked by atanasgagov 2 in Science & Mathematics ➔ Chemistry
It's been a long time since school but if it takes 1 calorie to lower 1 g of water by 1 degree C and dissolving KCl in water absorbs 4.1 kCal per mole (4100 calories) then it would take 6 moles of KCl to lower 1 kg of water by 25 degrees C. KCl is 74.55 g/mol so it would take 447.3 grams to lower the temperature of 1 kg of water by 25 degrees. That's in a perfect world, however. The solubility is affected by temperature and the saturation of the solution so it may not be possible to dissolve that much KCl into that volume of water. Also, the water will be absorbing energy from its surrounding environment as it cools, so that is another problem that will prevent you from reaching your goal in this experiment.
2006-07-07 06:56:26 · answer #1 · answered by ebk1974 3 · 1⤊ 0⤋
There is an equation for the collegative properties that allow you to calculate this but you need a constant for the KCl which should be in a table. This sounds like a question from your class in school. Sounds like you need to listen and read more and spend less time on the computer. I'm sure how to calculate the answer was in the text book you were given to read.
2006-07-08 00:23:28 · answer #2 · answered by gtoacp 5 · 0⤊ 0⤋
Don't bother calculating, just put it in the freezer, period! It would be as hard as ice in no time ;)
2006-07-07 13:40:33 · answer #3 · answered by gameplan_xtreme 4 · 0⤊ 0⤋