my sci fair proj. is
THE EFFECT OF DIFFERENT SOLUTES ON THE TEMPERATURE OF BOILING WATER.
the solutes i have used are :
sugar
salt
rock salt
baking soda
vinegar
eno
citric acid
and
disprin (the tablet)
the variation in the boiling pt is about 94 degrees C - 107 degrees celsius.
there is no drastic change
is that fine
is this project good
are my results valid ?
I AM CONFUSED!
2007-07-05 05:28:55 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
You are missing an important factor, how much of each of these? The boiling point is changed by the number of particles that are present. With salt, NaCl, it separates into Na+ and Cl- so there are more particles, than sugar that does not dissociate. However sugar is a much larger molecule so in the same amount, say 100 grams, there are fewer particles of a large molecular weight compound than a smaller compound mass material. When you say vinegar, you are talking about 5% acetic acid and 95 % water in your addition. Rock salt is generally CaCl2, which gives 3 particles as it comes apart. You really need to take a set amount of each one for comparison. Also a range from 94 to 107 is significant. Are you sure that it was a rolling boil each time? or the highest temperature that could be reached. What did the plain water boil at, at your location? You need a comparison.
2007-07-05 05:41:13 · answer #1 · answered by science teacher 7 · 1⤊ 0⤋
Yes, your results are definitely valid. The solutes are not going to change the boiling point by a lot, but you have documented your findings very well. That's a great project. If you still have doubt, you can always repeat your procedure and double check all the data points.
Hope you win 1st place!
2007-07-05 12:34:54 · answer #2 · answered by Lauren A 5 · 1⤊ 0⤋
Well, I think the gradation above 100 degrees is right but it be below as the solute particles will decrease the vapor pressure above the liquid and hence, b. point would be more. So correct the below part and DON'T GET CONFUSED.
2007-07-05 12:37:13 · answer #3 · answered by paras 2 · 1⤊ 0⤋
As they say, what you get is what you see. However, you might want to recheck your criteria for a "boiling" point, since one would not expect a depression of this parameter.
2007-07-05 12:32:46 · answer #4 · answered by cattbarf 7 · 2⤊ 0⤋
There doesn't have to be !!!!!!!!!!!
For more study up on Raoult's Law and Colligative properties.
2007-07-05 12:34:02 · answer #5 · answered by ag_iitkgp 7 · 1⤊ 0⤋