38.0kg mass of copper is melted to be cast into a graphite mold at a copper pipe foundtry. If the solid copper starts off at the normal melting temperature of copper and the liquid copper is put into the mold at the crystallization point of copper, how much heat is added to melt the copper? kJ
Melting point 1084.62 °C (from Wiki)
Heat fusion 13.26 kJ·mol^−1 (from wiki)
crystallization point of copper - ? not listed
38kg x 1kmol/63.55kg = 0.598kmol (if I did this right)
I would think that melting point and crystallization point would be the same.
q = heat needed = mass Cu x heat fusion
To determine the amount of heat required to melt the copper, we need to calculate the heat of fusion and the number of moles of copper.
Step 1: Calculate the number of moles of copper:
To determine the number of moles of copper, we divide the mass of copper (38.0 kg) by the molar mass of copper (63.55 g/mol).
38.0 kg x (1000 g/1 kg) = 38000 g
38000 g / 63.55 g/mol = 598.9 mol (rounded to three significant figures)
Step 2: Calculate the heat of fusion:
The heat of fusion for copper is given as 13.26 kJ/mol.
Step 3: Calculate the heat added to melt the copper:
To calculate the heat added, we multiply the number of moles by the heat of fusion.
598.9 mol x 13.26 kJ/mol = 7935 kJ (rounded to three significant figures)
Therefore, approximately 7935 kJ of heat is added to melt the 38.0 kg mass of copper.