Vocabulary
Heat of Vaporization
Heat of Fusion
Specific Heat
Review
100
What 2 phase changes are used for the heat of fusion formula?
Melting and Freezing
100
A certain amount of heat energy is required to vaporize 200 g of water at 100°C. If the heat of vaporization of water is 2,260 J/g, what is the total heat energy required?
452,000 J
100
How much heat is required to melt 200 g of ice at 0°C? (Given: Heat of fusion of ice is 334 J/g)
66,800 J
100
A 50 g sample of water is heated from 25°C to 35°C. If the specific heat capacity of water is 4.18 J/g°C, how much heat energy is absorbed?
2,090 J
100
Which subatomic particles are present in the nucleus of an atom?
Protons and Neutrons
200
What 2 phase changes are used for the heat of vaporization formula?
Evaporation and condensation
200
A sample of steam releases 339,000 J of heat energy as it condenses at 100°C. If the heat of vaporization of water is 2,260 J/g, what is the mass of the steam sample?
150 g
200
A sample of molten lead releases 3,675 J of heat energy as it solidifies at its melting point. If the heat of fusion of lead is 24.5 J/g, what is the mass of the lead sample?
150 g
200
An 80 g piece of copper is cooled from 150°C to 50°C. If the specific heat capacity of copper is 0.385 J/g°C, how much heat energy is released?
3,080 J
200
A sample of gas occupies 3.0 liters at a pressure of 2.0 atm. If the pressure is increased to 4.0 atm while keeping the temperature constant, what will be the new volume of the gas?
1.5 L
300
What is the definition of specific heat?
The amount of heat energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius.
300
A 500 g sample of ethanol requires 210,000 J of heat energy to vaporize at its boiling point. What is the heat of vaporization of ethanol?
420 J/g
300
A 250 g sample of silver requires 26,250 J of heat energy to melt at its melting point. What is the heat of fusion of silver?
105 J/g
300
A 200 g sample of ethanol is heated, absorbing 24,400 J of heat energy, which raises its temperature from 10°C to 60°C. What is the specific heat capacity of ethanol?
2.44J/g°C
300
Write the full electron configuration for the element iron (Fe), which has an atomic number of 26.
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
400
Explain the differences between open, closed, and isolated systems. Give an example of each.
Open System: Exchanges both energy and matter.
Closed System: Exchanges energy but not matter.
Isolated System: Exchanges neither energy nor matter.
400
A sample of liquid nitrogen absorbs 25 kJ of heat energy as it vaporizes at its boiling point. If the heat of vaporization of nitrogen is 199 J/g, what is the mass of the nitrogen sample? Round to the nearest hundredth.
125.63 g
400
A sample of molten aluminum releases 198 kJ of heat energy as it solidifies at its melting point. If the heat of fusion of aluminum is 396 J/g, what is the mass of the aluminum sample?
500 g
400
A sample of copper releases 3,080 J of heat energy as it cools from 150°C to 50°C. If the specific heat capacity of copper is 0.385 J/g°C, what is the mass of the copper sample?
80g
400
What is the molarity of a solution prepared by dissolving 58.5 g of sodium chloride (NaCl) in enough water to make 500 mL of solution? (Molar mass of NaCl = 58.5 g/mol)
2.0 M
500
What is the difference between heat and temperature? Define both in your answer.
Heat is energy in motion transferring between two substances or objects. Temperature measures the average kinetic energy of molecules.
500
A 0.75 kg sample of benzene requires 300 kJ of heat energy to vaporize at its boiling point. What is the heat of vaporization of benzene?
400 J/g
500
A 1 kg sample of gold requires 64.5 kJ of heat energy to melt at its melting point. What is the heat of fusion of gold?
64.5J/g
500
A 500 g sample of iron releases 33,750 J of heat energy as it cools from 200°C to 50°C. What is the specific heat capacity of iron?
0.450J/g°C
500
Draw all possible resonance structures for sulfur dioxide (SO₂).
