Comparing Silver and Gold Melting Points: Understanding Coefficient C/G °C

[natureboy]

So melting point of silver followed by coefficient c/g °c;
961.8
.056
Now golds;
1064
.031
Does that mean the silver melts first?

 

[Dr. Courtney]

It depends on your meaning of "first."

If you are raising T slowly so that both materials stay in near equilibrium with their surroundings, silver will melt first.

If one is adding heat at a constant rate, then one needs the heat of fusion and the initial temperature and masses to determine which would melt first.

 

[nasu]

No, it doesn't. It may, but it depends on other parameters. The size of the two samples, the rates of heat transfer into and out of the two samples.
And also, on what do you mean by "melts first". It is completely liquid or just "starting to melt".

 

[CWatters]

So melting point of silver followed by coefficient c/g °c;
961.8
.056
Now golds;
1064
.031

The figures with units c/g °c are for the specific heat capacity.

If you started with 1gram of both at room temperature (20c) and heated both samples it you would find it would take a different amount of energy for each one to reach melting point. For example it would take..

For silver... E = 1 * (961-20) * 0.056 = 53 calories
For gold... E = 1 * (1064-20) * 0.031 = 32 calories

So although silver has a lower melting point it takes more heat to get there.

So the answer depends on how the samples are heated as Dr Courtney said. If they are put in an oven together and the temperature increased slowly then Silver melts first. If you heat each one separately using something like a constant power electrical heater then gold melts first because it takes less energy.

 

[natureboy]

Thanks exactly what i was asking couldn't word it for the life of me though haha much appreciated