WorksheetsEnergy & Phase Changes Review II
Total questions: 40
Worksheet time: 44mins
What is the triple point of a substance?
The average of the melting point and boiling point of a substance at a pressure of 1.0 atm.
The minimum temperature at which the substance exists in the gas state.
The maximum pressure and temperature at which the substance exists in the liquid state.
The pressure and temperature at which the substance is in equilibrium between the solid, liquid, and gas states.
Where is the triple point located on a phase diagram?
In the exact middle of the diagram.
Along either the axis for temperature or the axis for pressure.
At the intersection of the lines that divide the regions for solid, liquid, and gas.
At the end of the line that divide the regions for liquid and gas.
A sample of ethanol is poured into a test tube, and then the test tube is sealed. What is the vapor pressure of the sample?
The pressure the ethanol vapor exerts in Earth's atmosphere.
The pressure the ethanol vapor exerts inside the test tube.
The pressure the liquid ethanol exerts inside the test tube.
The combined pressure the liquid ethanol and the ethanol vapor exert inside the test tube.
A student is planning an investigation to determine how the average kinetic energy of the particles of four different liquids changes over time as conditions change. Which tool does he need to measure average kinetic energy?
Balance
Calorimeter
Manometer
Thermometer
The graph shows the phase diagram of water. At which point can there be molecules that exhibit the properties of any of the three phases?
Point A
Point B
Point C
Point D
What conditions must exist for a liquid to boil?
Particles near the surface of the liquid must have enough kinetic energy to vaporize.
Collisions of particles must transfer enough energy to the container of the liquid.
Particles near the liquid's container must have enough kinetic energy to vaporize.
Particles throughout the liquid must have enough kinetic energy to vaporize.
Why does the boiling point of a liquid vary with atmospheric pressure?
Boiling occurs when the liquid temperature increases above air temperature.
Boiling occurs when vapor pressure decreases below the external pressure.
Boiling occurs when vapor pressure equals external pressure.
Boiling occurs when the vapor pressure of a liquid decreases to zero.
In general, how are the particles arranged in solids?
Randomly, and in positions that change gradually.
Randomly, and in positions that change rapidly.
In an orderly pattern, and in fixed positions.
In an orderly pattern that rapidly changes.
What phases are in equilibrium at a substance's melting point?
Solid and gas
Solid and liquid
Liquid and gas
Solid, liquid, and gas
What do the curved lines on a phase diagram represent?
The relationship between intermolecular forces and the temperature of a substance.
The relationship between the vapor pressure and the temperature of a substance.
The conditions of pressure and temperature at which the substance does not change phase.
The conditions of temperature and pressure at which two phases exist in equilibrium.
Which choice explains how evaporation lowers the temperature of a liquid?
Evaporation absorbs kinetic energy from the air, thus increasing the average kinetic energy of the remaining molecules of the liquid.
Evaporation removes the molecules of greatest kinetic energy from the liquid, thus decreasing the average kinetic energy of the remaining molecules.
Evaporation decreases the mass of the liquid, thus decreasing the average kinetic energy of the remaining liquid.
Evaporation decreases the volume of the liquid, thus decreasing the average kinetic energy of the remaining liquid.
Dry ice (solid carbon dioxide) lowers air temperature without melting into a liquid. This process is a practical use of what?
Condensation
Sublimation
Melting
Deposition
Which of the following will evaporate the fastest?
Water at 0°C
Water at 20°C
Water at 40°C
All samples will evaporate at the same rate.
Water could be made to boil at 105°C instead of 100°C by _____.
adding a lot of energy to the water.
increasing the external pressure.
decreasing the external pressure.
taking the sample to a higher altitude.
The normal boiling point of chloroform, which has a higher vapor pressure than water at 100°C, is _____.
higher than the normal boiling point of water.
lower than the normal boiling point of water.
the same as the normal boiling point of water.
unable to be measured.
Which of the following best describes the motion of the particles in a piece of steel?
None are moving.
A few are moving.
All are moving.
Most are moving.
Aqueous reactants of total mass of 50.0 grams, including water, are placed in a calorimeter. After the reaction occurs, the temperature inside the calorimeter increases by 3.0°C. How many joules of heat was released by the reaction? (°Cwater = 4.18 J/g •°C)
50 J
100 J
150 J
630 J
A 1.0 g sample of ethanol requires 2.4 J of heat to increase its temperature by 1°C. What is the constant 2.4 J/(g • °C)?
The heat capacity of ethanol.
The specific heat of ethanol.
The specific gravity of ethanol.
The heat of fusion of ethanol.
A 5.0 g sample of Substance X increases in temperature from 20.0°C to 22.0°C when it absorbs 9.6 J of heat. What is the specific heat of Substance X in J/(g • °C)?
0.096
0.48
0.96
1.5
On a cold night you use an electric blanket to warm your body. Which statement best describes the heat transfer in this process? Assume your body is the system.
Heat flows from the blanket into your body in an exothermic process.
Heat flows from the blanket into your body in an endothermic process.
Heat flows from the blanket in a process that is neither exothermic or endothermic.
Heat does not flow between the blanket and your body.
A chunk of silver has a heat capacity of 42.8 J/°C and a mass of 181 g. Calculate the specific heat of silver.
7750 J/(g °C)
0.940 J/(g °C)
0.236 J/(g °C)
1.96 J/(g °C)
How much heat must be removed to freeze a tray of ice cubes at 0°C? The mass of the water is 225 g.
34.0 kJ
75.1 kJ
107 kJ
198 kJ
Match statement item with the correct item below:
Vaporization at the surface of a liquid that is not boiling.
vaporization
melting point
boiling point
evaporation
Match statement item with the correct item below:
The conversion of a liquid to a gas below the boiling point
vaporization
melting point
boiling point
evaporation
Match statement item with the correct item below:
The temperature at which the vapor pressure of a liquid is equal to the external pressure.
vaporization
melting point
boiling point
evaporation
Match statement item with the correct item below:
The temperature at which the vapor pressure of a liquid is equal to 1 atmosphere.
vaporization
melting point
normal boiling point
evaporation
Match statement item with the correct item below:
The temperature at which a solid changes into a liquid.
vaporization
melting point
normal boiling point
evaporation
Match statement item with the correct item below:
The change of a solid directly to a vapor.
vaporization
melting point
sublimation
evaporation
Consider the particles in a sample of matter. The average kinetic energy of the particles is directly proportional to which property of the sample?
The mass of the sample in kilograms.
The temperature of the sample in degrees Celsius.
The temperature of the sample in kelvins.
The density of the sample in grams per cubic centimeter.
The heat of molecules
The average kinetic energy of molecules
Thermal energy
What equation correctly measures the change in thermal energy?
Which symbol represents thermal energy in the specific heat formula?
There are four different sized cups of hot chocolate (see image). The temperature of the hot chocolate in each cup is 25°C. Which cup has the most thermal energy?
All three cups are the same temperature, so each has the same amount of thermal energy.
Thermal energy is measured in which unit?
Copper, stainless steel, carbon steel, and zinc are heated using 10,000 J of thermal energy. Which material would experience the largest change in temperature?
A high specific heat means that _____.
the substance requires less energy to change temperature.
the substance requires more energy to change temperature.
the substance heats up very quickly.
Aluminum foil is removed from the oven, cooling from 100°C to 50°C. What is the change in temperature?
Copper, stainless steel, carbon steel, and zinc were heated using 10,000 J of thermal energy. Based on the chart, which material would experience the smallest change in temperature?
One pan contains 100 mL of water, while another pan contains 1000 mL of water. 4000 J of energy are added to each pan. Which pan experiences the greater change in temperature?
100 mL pan
1000 mL pan
Both pans are made of the same material, so both have the same temperature.
The temperature of both pans will decrease.
The lowest possible temperature on the Kelvin scale is known as _____.
the boiling point
the freezing point
the no temperature zone
