What melts ice the fastest

[jazmath]

Hello,

I would like to know what melts ice the fastest and why...sand, salt, pepper, or sugar. I would greatly appreciate any help you can give me.

jazmath

[ToddC]

I don't know how complicated you want this to be. There are multiple factors at play in the rate of melting. First, there is the latent heat of melting ice, 80 cal/g. So, you need to figure out the amount of energy required to melt a known mass of ice.
Second is the amount of energy generated during solublization; the heat of solution - which may be exothermic or endothermic depending on the substance dissolving in the water.
Third is the cryoscopic constant of the substance - the amount by which a substance decreases the freezing point of ice.

Frankly, the short answer is that you will get the best information by experiment. Intuitively, I expect salt to be the substance that melts ice fastest, but that's based on my experience - no calculations involved.

[Craig_Bridge]

sand, salt, pepper, or sugar

Sand won't chemically react with ice. If the sand is colder than the melting point of the ice, the ice will not melt. On the other hand, you can heat sand to very high tempeartures without it melting the sand (forming glass) and very hot sand would certainly melt ice just by thermal transfer. NaCl Salt will chemically react (ionize) with ice giving off heat along with depressing the freezing point as long as the temperature is above some point at which the reaction won't occur. Pepper and sugar won't chemically react with ice; however, if either is hot, thermal transfer may melt the ice. In the case of sugar and water, the freezing point will be lowered slightly but that can't happen until the ice melts somehow. Given all of this, which happens faster would be a function of the initial starting states interms of quantities and temperatures. In other words, it depends...