Re: Why does sugar not increase the boiling point of water as much as salt does

Thank you for your interesting question.
The increase in boiling point depends on the number of molecules you add to the 
liquid. Now salt is a very small molecule. In addition it splits into two 
particles when in water, the sodium atom and the chloride atom. In numbers: if 
you add 6g of salt into water you add about 4,400,000,000,000,000,000,000  (4.4 * 
10^22) particles to the water. 
Sugar has a molecular weight that is 3 times larger than that of salt. It does 
not split up in different particles when in water. So adding 6 g sugar into water 
you add around 700,000,000,000,000,000,000 particles (7.3 * 10^21) to the water.  
Still a huge number, but considerably less than with salt. To get the same effect 
with sugar that you get with salt, you will have to use about 6 times as much 
sugar as salt. 
The same is true in principle with lowering the freezing point of liquids. That 
is the reason why we use salt in winter on our streets and not sugar - as we 
would need 6 times as much for the same effect. But it would work with sugar too, 
if you use enough of it. 

Hope that helps.
Jurgen Ziesmann