Review Questions: Specific Heat, Heat of Fusion/Vaporization
How much heat is lost when a 64 g piece of copper cools from 375 degrees Celsius, to 26 degrees Celsius? (The specific heat of copper is 0.38452 J/g x oC).
-8588.63 J
The temperature of a 55 gram sample of a certain metal drops by 113 degrees Celsius as it loses 3500 Joules of heat. What is the specific heat of the metal?
0.56 J/g x degrees Celsius
Determine the specific heat of a certain metal if a 450 gram sample of it loses 34 500 Joules of heat as its temperature drops by 97 degrees Celsius.
0.79 J/g x degrees Celsius
How much energy is required to vaporize 234.5 g of water? (The heat of vaporization is of water is 540 cal/g.)
1.3 x 10^5 cal
How many joules of heat are required to raise the temperature of 550 g of water from 12.0 degrees Celsius to 18.0 degrees Celsius? (specific heat of water is 4.18 J/g x degrees Celsius)
13807.2 J
How much change in temperature would the addition of 35,000 Joules of heat have on a 538.0 gram sample of copper? (specific heat of copper is 0.387 J/g x degrees Celsius)
169.0 degrees Celsius
8750 J of heat are applied to a piece of aluminum, causing a 56.0 degrees Celsius increase in its temperature. The specific heat of aluminum is 0.9025 J/g x degrees Celsius. What is the mass of the aluminum?
173 grams
How many degrees would the temperature of a 450 g piece of iron increase if 7600 J of energy are applied to it? (The specific heat of iron is 0.4494 J/g x degrees Celsius)
37.6 degrees Celsius
Find the mass of a sample of water if its temperature dropped 24.8 degrees Celsius when it lost 870 J of heat. (specific heat of water is 4.18 J/g x degrees Celsius)
8.38 grams
1.10 J/g
Ethanol (C2H5OH) very easily changes from a liquid to a gas. If 29.34g of ethanol uses 32.23J of energy what would its Hvap be?
11500 J
For a 500g block of lead (Pb) to melt, how much energy is needed? Hfus of lead is 23 J/g.
120240 J
How much heat is required to melt 360 g of solid water? Important constant: Hfus of water is 334 J/g
54168 J
How much heat is required to vaporized 24 g of liquid water? Hvap of water is 2260 J/g
2.4 J/g
In order for 5g liquid Hydrogen to become a solid, 12J of energy must be removed. What is the Hfus for the element, Hydrogen?
3035715 J
Iron is the heaviest metal vaporized in the sun. Its Hvap is 6071.43 J/g. How much heat is needed to turn (keep) .5 kilogram, 500 grams of iron into a gas?
84.75 J
Mercury is a metal that is a liquid at room temperature. In order to solidify 7.5g of it, how much energy needs to be removed? Hfus of Hg is 11.3 J/g.
Which formula is for no phase change?
Q = SH(m)(
What is the formula for the Eph at 0 degrees Celcius?
Q = m x Hfus
What is the formula for Eph at 100 degrees Celcius?
Q = m x Hvap
Solid to liquid
The phase transition that happens during heat of fusion
Liquid to gas
The phase transition that happens during heat of vaporization
Endothermic
Type of reaction where heat is absorbed
Exothermic
Type of reaction where heat is released
1376.67 J/g
What is the heat of vaporization of ammonia (NH3) if 0.15 g of it requires 206.5 J for evaporation?
