chemistry

posted by .

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes?
The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol.

2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3.

• chemistry -

Andrew, I think I answered #1 earlier.
#2.
First calculate the volume of a bar of Cu that is 80 cm x 10 cm x 12 cm.
Volume = Length x width x depth. in cubic centimeters.

mass = density x volume. You have the density and you know the volume, you can calculate mass.
heat to melt = mass x heat of fusion.
Since the heat of fusion is listed in J/mole, you must change the mass of copper to moles from grams. moles = grams/molar mass.

Similar Questions

1. chemistry

How much heat is required to vaporize 3.50L of at its normal boiling point?
2. chemistry

How much heat is required to vaporize 3.50L of at its normal boiling point?
3. chem

The normal melting point of copper is 1357 K and heat of fusion of Cu is 13.05 KJ. How much heat, in kilojoules, is evolved when a 3.70 kg sample of of molten Cu freezes?
4. chemistry

How much heat, in kilojoules, is evolved when a 3.70 kg sample of molten Cu freezes?
5. chemistry

2.) How much heat must be absorbed at 1357 K to melt a bar of copper (80 * 10 * 12 cm) assume d = 8.93 g/cm^3. The normal boiling point is 1357 K, and heat of fusion is 13.05 KJ/mol.
6. Chem 2 enthalpy

How much heat is evolved when 25.5 g of benzene freezes at 5.5 Celcius (molar heat of fusion is 9.94 kJ/mol and molar mass of benzene= 78.0 g/mol)
7. Chemistry

Lead has a melting point of 327ºC, its specific heat is J/g•deg, and its molar enthalpy of fusion is 4.80 kJ/mol. How much heat, in kilojoules, will be required to heat a 500.0-g sample of lead from 23.0ºC to its melting point …
8. Chemistry

Lead has a melting point of 327ºC, its specific heat is J/g•deg, and its molar enthalpy of fusion is 4.80 kJ/mol. How much heat, in kilojoules, will be required to heat a 500.0-g sample of lead from 23.0ºC to its melting point …
9. Chemistry

Ethanol (C2H5OH) has been produced since antiquity by the fermentation of fruits and vegetables. Given the following data, if 5.87 kJ of energy are transferred to 13.3 g of frozen ethanol at -130.0 °C, what is the final temperature …
10. Physical Science

Lead is a soft, dense metal with a specific heat of 0.117 J/goC, a melting point of 328.0 oC, and a heat of fusion of 23012 J/g. How much heat (in kilojoules) must be provided to melt a 350.0 kg sample of lead that is initially at …

More Similar Questions