melting mercury?

Question

How much heat is required to melt 50 g of mercury at -45 degrees Celsius to 425 degrees Celsius. Describe the whole process from the molecular level. (melting point - 39 degrees Celsius, boiling point - 357 degrees Celsius, specific heat - 0.033 kcal/kg-degree C, heat of fusion - 11.8 kJ/kg, heat of vaporization - 292 kJ/kg)

Answer 1

Melting Hg is same as melting ice. The solid has to heat up from the starting temp to the mp (Cp solid). Then the latent heat of fusion is added to convert the solid to liquid. Then heat is needed to heat up the liquid (Cp liquid).

Check your units and it is simple math. Good luck

Answer 2

Here it is for the 2nd time.

For this calculation you need 5 steps and, Like most people, you'll probably find the Specific and Latent Heats on the Internet.

1..the Specific heat of Hg from -45°C to -39°C (Heating))
= 6°C x 50g x S.H.(J/g/°C). = Joules.
2...The Latent heat of Fusion for Hg
= 50g x L.H.(J/g). = Joules. (Melting)
3...The Specific Heat of liquid Hg from -39°C to its Boiling point at 357°C.
= 50g x S.H.(J/g/°C) x 396°C = Joules. (Heating)
4...The Latent Heat of Vaporisation of Hg.
= 50g x L.H. (J/g). = Joules. (Vaporising)
5.. The Specific Heat of Hg Vapour from 357°C to 425°C.
= 50g x S.H.(J/g/°C) x 68°C = Joules. (Heating)

Now, add together all the Joules from calculations ...1,2,3,4,and 5 to find the total quantity of heat required to complete the process.

Answer 3

Note that the mercury will be a vapor at 425° C.