Question
Which statements correctly defend or dispute his conclusion?
He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.
Answers
GPT-4o mini
To evaluate the statements regarding the conclusion about dissolving salt in water and evaporating water, let's clarify the nature of each process:
1. **Dissolving salt in water** is a **physical change**. The salt dissociates into its ionic components in the water, but no new substance is formed, and the process is reversible.
2. **Evaporating water** is also a **physical change**. Water changes from a liquid to a gas, but again, no new substance is formed, and this process is also reversible.
3. **Formation of a solid** during a chemical change would indeed indicate a new substance is formed. However, in the case of salt dissolved in water, the solid (salt) can be recovered by evaporation, reaffirming that both processes are physical changes.
Given these clarifications, we can analyze the provided statements:
1. **"He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred."**
This statement is **incorrect** because evaporation is a physical change, not a chemical change.
2. **"He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred."**
This statement is **incorrect** because dissolving salt in water is a physical change, not a chemical change.
3. **"He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change."**
This statement is **correct**. Both processes are physical changes and the reversibility supports this conclusion.
4. **"He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change."**
This statement is **incorrect**. Both processes are physical changes, not chemical changes.
Thus, the correct defense against his conclusion would be statement 3.
1. **Dissolving salt in water** is a **physical change**. The salt dissociates into its ionic components in the water, but no new substance is formed, and the process is reversible.
2. **Evaporating water** is also a **physical change**. Water changes from a liquid to a gas, but again, no new substance is formed, and this process is also reversible.
3. **Formation of a solid** during a chemical change would indeed indicate a new substance is formed. However, in the case of salt dissolved in water, the solid (salt) can be recovered by evaporation, reaffirming that both processes are physical changes.
Given these clarifications, we can analyze the provided statements:
1. **"He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred."**
This statement is **incorrect** because evaporation is a physical change, not a chemical change.
2. **"He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred."**
This statement is **incorrect** because dissolving salt in water is a physical change, not a chemical change.
3. **"He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change."**
This statement is **correct**. Both processes are physical changes and the reversibility supports this conclusion.
4. **"He is incorrect. Dissolving salt in water and evaporation of the water are both chemical changes. The reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change."**
This statement is **incorrect**. Both processes are physical changes, not chemical changes.
Thus, the correct defense against his conclusion would be statement 3.