1.
Which of the following could solid ice become if heat energy is added? (Check all that apply)
Correct Answer(s)
B. Liquid Water
C. Vapor
Explanation
When heat energy is added to solid ice, it undergoes a phase change and can become either liquid water or vapor. This is because heat energy causes the ice particles to gain kinetic energy and move faster, breaking the intermolecular bonds that hold the solid ice structure together. As a result, the ice melts and turns into liquid water. If more heat energy is added, the liquid water can further evaporate and turn into vapor. Therefore, both liquid water and vapor are possible outcomes when heat energy is added to solid ice.
2.
If isopropyl alcohol is a liquid at room temperature (25 degrees Celsius), which of the following must its boiling point be?
Correct Answer
D. 82 Degrees Celsius
Explanation
Isopropyl alcohol is a liquid at room temperature (25 degrees Celsius), which means its boiling point must be higher than 25 degrees Celsius. Among the given options, the only temperature that is higher than 25 degrees Celsius is 82 degrees Celsius. Therefore, the boiling point of isopropyl alcohol must be 82 degrees Celsius.
3.
Which of the following terms identifies the change from a liquid to solid?
Correct Answer
B. Solidification
Explanation
Solidification is the process by which a substance changes from a liquid state to a solid state as it loses heat. During solidification, the particles in the liquid slow down and arrange themselves into a more ordered and tightly packed structure, forming a solid. This transition occurs when the temperature of the substance decreases to the point where its thermal energy is not sufficient to maintain the random movement of particles associated with the liquid phase.
The opposite process, where a solid changes to a liquid, is known as "melting." Solidification and melting are two fundamental phase transitions that occur in matter as it experiences changes in temperature.
4.
Oxygen becomes a gas at -183 degrees Celsius. We would call this temperature?
Correct Answer
A. Boiling point
Explanation
The correct answer is boiling point. Oxygen becomes a gas at -183 degrees Celsius, which is the temperature at which it boils and changes from a liquid to a gas state.
5.
The following occurs when heat energy is removed:Gas ---(A)--> Liquid ---(B)---> SolidWhat would be the phase changes for A and B respectfully?
Correct Answer
C. Condensation, Freezing
Explanation
When heat energy is removed, the gas phase changes into a liquid phase, which is called condensation. This corresponds to option C. Then, the liquid phase changes into a solid phase, which is called freezing. This corresponds to option D. Therefore, the correct phase changes for A and B respectively are condensation and freezing.
6.
Examine the following sequence of phase changes:Solid ---> Liquid ---> GasWould we need to ADD or REMOVE heat energy?
Correct Answer
A. Add heat energy
Explanation
In order to change a solid into a liquid and then into a gas, heat energy needs to be added. This is because heat energy is required to break the intermolecular forces holding the particles together and allow them to move more freely. Therefore, in this sequence of phase changes, heat energy needs to be added.
7.
Freezing is to solid, as sublimation is to ______________________
Correct Answer
C. Gas
Explanation
Freezing is the process of a substance changing from a liquid to a solid state, while sublimation is the process of a substance changing directly from a solid to a gaseous state without passing through the liquid state. Therefore, the analogy suggests that just as freezing is associated with the transformation from liquid to solid, sublimation is associated with the transformation from solid to gas.
8.
If chemical "X" had the following physical properties:
Melting Point = - 32 Degrees Celsius
Boiling Point = -11 Degrees Celsius
what state of matter would you find Chemical "X" if the temperature was 0 Degrees Celsius?
Correct Answer
B. Liquid
Explanation
At 0 degrees Celsius, which is the freezing point of water, chemical "X" would be in a liquid state. This is because its temperature is above its melting point (-32 degrees Celsius), but below its boiling point (-11 degrees Celsius). In this temperature range, the substance is in a liquid state.
9.
When isopropyl alcohol was spilled over the counter top and quickly disappeared, what phase change occurred?
Correct Answer
A. Evaporation
Explanation
When isopropyl alcohol is spilled over a counter top and quickly disappears, it indicates that a phase change of evaporation has occurred. Evaporation is the process by which a liquid, in this case, isopropyl alcohol, changes into a gas or vapor state at a temperature below its boiling point. The rapid disappearance of the spilled alcohol suggests that it has transformed into a gas and dispersed into the surrounding air.
10.
A student noticed frost was on the ground at 6:30 a.m. but noticed it disappeared by 8:30 a.m. What phase change was responsible for turning the frost into water vapor?
Correct Answer
C. Sublimation
Explanation
The phase change responsible for turning the frost into water vapor is sublimation. Sublimation is the process in which a solid directly changes into a gas without going through the liquid phase. In this case, the frost on the ground skipped the melting phase and directly turned into water vapor due to the low temperature and pressure conditions.