Heat
What is the heat required to melt 150.0g of ice?
50,100 J
What is the heat required to boil 80.0 g of water?
180,800 J
The average kinetic energy of the particles in a sample of matter is expressed as
Temperature
What is the heat required to melt a 50.0g solid with a heat of fusion equal to 400 J/g?
20,000 J
What is the heat required to melt 15.0g of ice?
5,010 J
500.0 J of heat is absorbed as water is melted. What is the mass of the water?
1.50 g
What is the heat required to boil 30.0 g of a liquid with a heat of vaporization equal to 1,150 J/g?
34,500 J
1500.0 J of heat is absorbed to evaporate water. What is the mass of the water?
0.66 g
What is the specific heat capacity of a 40.0 g liquid that was heated from 15°C to 90°C, absorbing 4000 J of heat in the process?
1.33 J/g°C
What is the heat of vaporization of a 5.0 g sample that absorbs 300.0 J of heat while boiling?
60.0 J/g
The particles in which sample have the lowest average kinetic energy? What is your reasoning?
(1) 50. g of sulfur at 273 K
(2) 40. g of aluminum at 298 K
(3) 30. g of sulfur at 303 K
(4) 20. g of aluminum at 323 K
(1) 50. g of sulfur at 273 K
A liquid with a specific heat capacity equal to 5.62 J/g°C is heated from 25°C to 80°C. Knowing that 678J were absorbed in the process, what is the mass of our liquid?
2.19 g
A 60.0 g sample of water was heated from 20°C to 80°C. How much heat was required?
15,048
What is the specific heat capacity of a 52.0 g solid that absorbed 6300.0 J of energy, causing the temperature to rise by 45°C?
2.69 J/g°C
List three phase changes that are exothermic, and three phases that are endothermic.
exothermic: freezing, condensation and deposition.
endothermic: melting, vaporization and sublimation.
25.0 grams of a compound at its boiling point is converted to a gas by the addition of 34,400 Joules. What is the heat of vaporization for this compound, in Joules per gram?
1,376 J/g
Show a numerical setup for calculating the heat in joules required to completely vaporize 300.0 g of water at 90°C.
q = (300.0 g) x (2260.0 J/g)
How much heat is absorbed by a 20.0 g boulder as energy from the sun causes its temperature to change from 10°C to 29°C? (Specific heat capacity is 0.1 J/gºC)
38.0 J
Show the numerical setup to calculate the heat in joules required to raise the temperature of a substance from 35°C to 46°C, with a mass of 50.0 g and a specific heat capacity equal to 4.67 J/g°C.
q = (50.0 g) x (4.67 J/g°C) x (11°C)
What is the total number of joules released when a 5.00-gram sample of water changes from liquid to solid at 0°C?
1,670 J
Solid A has a specific heat capacity equal to 6.76 J/g°C, while Solid B has a specific heat capacity of 9.78 J/g°C.
Which solid will take longer to melt? explain your answer.
Solid B will take longer to melt: more heat is required to raise the temperature.
A 4.0 g coin of copper absorbed 9.24 J of heat. What was the final temperature of the copper if the initial temperature was 25°C? The specific heat of copper is 0.385 J/g°C.
31°C
A 56.0 g substance absorbs 672.0 J of heat and has a specific heat capacity equal to 3.00 J/g°C. If this substance has an initial temperature equal to 25°C, what is the final temperature?
29°C
What is the initial temperature of a substance that has a mass of 56.0 g, a specific heat capacity equal to 6.00 J/g°C, an final temperature of 32°C and absorbed 1,680 J of heat?
27°C
Liquid X has a specific heat capacity equal to 6.56 J/g°C. Liquid Y has a specific heat capacity equal to 4.32 J/g°C.
Which liquid will boil more quickly? explain your reasoning.
Liquid Y: it takes less heat energy to raise the temperature to its boiling point.