A reaction occurs between two liquid substances in a sealed container. Based on the law of conservation of mass, what will happen to the mass of the sealed container and its contents overall?
- A. If the reaction produces a gas, the mass will decrease.
- B. If the reaction produces a solid, the mass will increase.
- C. If the reaction produces a liquid, the mass will increase as well.
- D. No matter what the reaction produces, the mass will remain the same.
Correct Answer & Rationale
Correct Answer: D
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, regardless of whether a gas, solid, or liquid is produced, the total mass of the sealed container and its contents will remain constant. Option A is incorrect; while gas may escape in an open system, a sealed container retains all products, so mass does not decrease. Option B is misleading; while a solid may form, it does not increase the total mass, as the mass of reactants equals that of products. Option C also misinterprets mass conservation; producing a liquid does not add to the total mass. Thus, the overall mass remains unchanged throughout the reaction.
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Therefore, regardless of whether a gas, solid, or liquid is produced, the total mass of the sealed container and its contents will remain constant. Option A is incorrect; while gas may escape in an open system, a sealed container retains all products, so mass does not decrease. Option B is misleading; while a solid may form, it does not increase the total mass, as the mass of reactants equals that of products. Option C also misinterprets mass conservation; producing a liquid does not add to the total mass. Thus, the overall mass remains unchanged throughout the reaction.
Other Related Questions
Which of the following best describes a comet?
- A. A small planet orbiting the Sun between Mars and Jupiter.
- B. A chunk composed primarily of metal that enters Earth's atmosphere.
- C. A chunk composed primarily of rock, ice, and dust orbiting the Sun in an elliptical path.
- D. A dark region that appears periodically on the surface of the Sun.
Correct Answer & Rationale
Correct Answer: C
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Which of the following is an example of physical weathering?
- A. The cracking of a rock caused by the freezing and thawing of water.
- B. Sediments being transported in a stream.
- C. A sandbar forming in a stream.
- D. Acid rain dissolving a statue.
Correct Answer & Rationale
Correct Answer: A
Physical weathering involves the mechanical breakdown of rocks without changing their chemical composition. Option A exemplifies this, as the freezing and thawing of water causes rocks to crack due to the expansion of ice, a clear physical process. Option B describes sediment transport, which is a process related to erosion rather than weathering. Option C refers to the formation of a sandbar, a depositional feature resulting from sediment accumulation, not weathering. Option D involves chemical weathering, where acid rain alters the chemical structure of the statue, distinguishing it from the physical processes in option A.
Physical weathering involves the mechanical breakdown of rocks without changing their chemical composition. Option A exemplifies this, as the freezing and thawing of water causes rocks to crack due to the expansion of ice, a clear physical process. Option B describes sediment transport, which is a process related to erosion rather than weathering. Option C refers to the formation of a sandbar, a depositional feature resulting from sediment accumulation, not weathering. Option D involves chemical weathering, where acid rain alters the chemical structure of the statue, distinguishing it from the physical processes in option A.
Which of the following best describes a chemical change?
- A. The melting of ice into water.
- B. The breaking of a piece of glass.
- C. The burning of wood in a fireplace.
- D. The bending of a metal wire.
Correct Answer & Rationale
Correct Answer: C
A chemical change involves a transformation that alters the substance's chemical structure. Option A describes a physical change, where ice melts into water without changing its chemical composition. Option B also represents a physical change; breaking glass does not alter the glass's chemical identity. Option D, bending a metal wire, is another physical change, as the metal's composition remains the same despite its shape being altered. In contrast, burning wood in a fireplace (Option C) results in new substances, such as ash and gases, indicating a chemical change has occurred.
A chemical change involves a transformation that alters the substance's chemical structure. Option A describes a physical change, where ice melts into water without changing its chemical composition. Option B also represents a physical change; breaking glass does not alter the glass's chemical identity. Option D, bending a metal wire, is another physical change, as the metal's composition remains the same despite its shape being altered. In contrast, burning wood in a fireplace (Option C) results in new substances, such as ash and gases, indicating a chemical change has occurred.
Which THREE of the following are considered sources of freshwater?
- A. Rivers
- B. Aquifers
- C. Oceans
- D. Glaciers
Correct Answer & Rationale
Correct Answer: A,B,D
Rivers, aquifers, and glaciers are all significant sources of freshwater. Rivers provide accessible water for ecosystems and human use, while aquifers store water underground, making it available for wells and springs. Glaciers, as large ice formations, hold substantial freshwater reserves that can feed rivers and lakes as they melt. In contrast, oceans are primarily saline and not suitable for direct human consumption or most agricultural uses. Therefore, they do not qualify as sources of freshwater, making options A, B, and D the correct choices.
Rivers, aquifers, and glaciers are all significant sources of freshwater. Rivers provide accessible water for ecosystems and human use, while aquifers store water underground, making it available for wells and springs. Glaciers, as large ice formations, hold substantial freshwater reserves that can feed rivers and lakes as they melt. In contrast, oceans are primarily saline and not suitable for direct human consumption or most agricultural uses. Therefore, they do not qualify as sources of freshwater, making options A, B, and D the correct choices.