Law of Conservation of Matter Quick Check
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Question
A student combines two liquids in a beaker. She observes that the mass of the combined liquid is less than the mass of the two separate liquids. The student claims that this observation shows that matter is not conserved in chemical reactions. Which statement explains why the student’s claim is incorrect?(1 point)
Responses
The reaction produced a gas that escaped the beaker.
The reaction produced a gas that escaped the beaker.
The product contained fewer atoms than the reactants.
The product contained fewer atoms than the reactants.
The combined liquid was warmer than the two separate liquids.
The combined liquid was warmer than the two separate liquids.
The reaction did not change the physical properties of the liquids.
The reaction produced a gas that escaped the beaker.
The correct statement that explains why the student's claim is incorrect is: The reaction produced a gas that escaped the beaker.
To determine why the student's claim is incorrect, we need to analyze the statements provided as possible explanations.
Statement 1: "The reaction produced a gas that escaped the beaker."
This statement suggests that the mass loss observed could be due to a gas being produced and escaping the beaker. If the gas was not accounted for in the mass measurement, it could explain the apparent loss of mass. This supports the conservation of matter because the total mass of the reactants and products remains the same, considering the escaped gas.
Statement 2: "The product contained fewer atoms than the reactants."
This statement proposes that the combined liquid has fewer atoms than the separate liquids. However, in a chemical reaction, atoms are not lost or created. The total number of atoms before and after the reaction must remain the same, supporting the conservation of matter. Therefore, this statement does not support the student's claim.
Statement 3: "The combined liquid was warmer than the two separate liquids."
This statement relates to the temperature of the liquids but does not provide an explanation for the observed loss of mass. Therefore, it does not address the student's claim and is irrelevant in determining the validity of their statement.
Statement 4: "The reaction did not change the physical properties of the liquids."
This statement focuses on the physical properties of the liquids and does not directly explain the loss of mass. While it is possible that the reaction did not change the physical properties, it does not address or refute the student's claim about the conservation of matter.
Based on the explanations, statement 1 is the most plausible explanation for the observed loss of mass. The gas produced in the reaction may have escaped the beaker, leading to the lower mass measurement. Therefore, the correct answer is: "The reaction produced a gas that escaped the beaker."