Energy
How many Joules of heat would be required to completely melt 5.00 grams of H2O(s) to H2O(l) at 0*C?
1,670
The heat of fusion of a compound is 126 Joules per gram. What is the total number of Joules of heat that must be absorbed by a 15.0-gram sample to change the compound from solid to liquid at its melting point?
1,890 J
Convert 1357 to kilojoules
1.357 kj
The temperature of a sample of water changes from 10*C to 20*C when the sample absorbs 418 joules of heat. What is the mass of the sample?
10g
How many Joules of heat energy are released when 50.0 grams of water are cooled from 70*C to 60*C?
2100 J
At which temperature would atoms of a He(g) sample have the greatest average kinetic energy?
37*C or 310K
At which temperature would the molecules of a one gram sample of water have the lowest average kinetic energy?
5 K
Which temperature is equal to 120 K?
-153°C
Which temperature represents absolute zero?
0 Kelvin
Which of these processes is always exothermic?
Combustion
When ammonium chloride dissolves in water the temperature falls. The type of energy change is described as?
Endothermic
The average kinetic energy of water molecules increases when
H2O (l) at 10*C changes to H20 (l) at 20*C
Which phase change is exothermic?
H2S (g) > H2S (l)
Which term represents a form of energy?
Heat
Object A at 40*C and object B at 80*C are placed in contact with each other. Which statement describes the heat flow between the objects?
Heat flows from object B to object A.
What occurs when 35-gram aluminum cube at 100*C is placed in 90. Grams of water at 25*C in an insulated cup?
Heat is transferred from the aluminum to the water and the temperature of the water increases.
Which statement defines the temperature of a sample of matter?
Temperature is a measure of the average kinetic energy of a particles.
Which statement defines the temperature of a sample of matter?
Temperature is the measure of the average kinetic energy of the particles.
Which unit is used to express the energy absorbed or released during a chemical reaction?
Joule
Which unit is used to express the energy absorbed or released during chemical reaction?
Joule
Given the balanced equation representing a reaction: 2H20 (l) + energy > 2H2 (g) + O2 (g) What occurs as a result of this reaction?
The reaction is endothermic and energy is absorbed
Which type of energy is associated with the random motion of particles in a sample of gas?
Thermal energy
A student observed that the temperature of water increased when a salt was dissolved in it. The student should conclude that dissolving the salt was
an exothermic reaction
The chemical change when a fuel burns can be described as?
an exothermic reaction
The three forms of energy are
chemical, thermal and electromagnetic
The heat energy required to change a unit mass of a solid into a liquid at constant temperature is called:
heat of fusion
