If one ice cube was placed in each cup of water, salt water, and pepsi, which ice cube would melt faster?

Question

If you place an ice cube in a cup of water, and then anotehr one in a cup of pepsi, and other in a cup of salt water, which ice cube would melt faster and why?

Answer 1

pepsi, coz it gets warmer sooner than the ice

and because of the carbonation.

salt water on the other hand also would get warmer sooner than the ice.

hmm..

Answer 2

Salt water.Salt causes ice to melt. That's why they use it on icy roads.

Answer 3

salt

Answer 4

I'd say pepsie because the  carbonated water in the pepsi would displace the oxygen of the H2O of the ice. Carbon dioxide displaces oxygen vey quickly

Answer 5

Probably the pepsi due to the carbonation and it also carries alot of sodium on its own.

Answer 6

IDK.  I'd have to try it.  I GUESS that salt water will be fastest.

Here's my description of the melting (I'm not an expert)

1.  Conduction of heat from liquid to surface of ice causes temperature to rise.  Some melting begins fluid temperature close to surface drops.

2.  Convection in liquid allows replacement of cooler liquid with warmer liquid.  Cooler liquid is denser and drops towards bottom.

3.  As melting proceeds a temperature and concentration gradient are dynamically set up.  The warmer water has to move (or diffuse) past the colder water to reach the surface of the cube.  Salt also has to get to the surface to enable more rapid melting.

Salt concentration gradient helps mix the liquid. faster=F

Salt increases thermal conductivity of water. F

Salt increases heat capacity of water. F

Salt increases viscosity of water. slows=S

Sugar concentration gradient helps mix the liquid.F

Sugar decreases thermal conductivity of water. S

Sugar decreases heat capacity of water. S

Sugar increases viscosity of water. S

CO2 bubbles help mix the liquid. F

CO2 decreases thermal conductivity of water. S

CO2 decreases heat capacity of water. S

So, thats why I guess Salt water. (Heat capacity is amount of heat the liquid can carry, thermal conductivity is the speed it carries it and viscosity is the difficulty the liquid has in flowing)

One interesting experiment would be to try a real concentrated cool solution of salt water.  What if the density of the salt water was higher than the melted ice water and so the melt water pooled around the cube?  It would act as a (kind of) blanket around the cube and slow down the melting (maybe).!?  So, I think hot salt water will melt the cube faster than the others, but the effect of the bubbles in pepsi might help keep the liquid mixed and also speed up the melting.  As I said IDK, but I guess salt water.

The experiment might depend on how carefully you insulated the cups and how carefully you prevented any vibrations from disturbing them - since vibrations and drafts will cause currents in the cups.

Edit - of course all three liquids have to be at same temperture for this to be true.  carbonation bubbles cause the pepsi to cool a little so it might not be that easy to start all 3 out at the same temperature....