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)

Question

Responses

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 did not change the physical properties of the liquids.

The product contained fewer atoms than the reactants.
The product contained fewer atoms than the reactants.

The reaction produced a gas that escaped the beaker.

Answer 1

The correct statement that explains why the student’s claim is incorrect is:

The reaction produced a gas that escaped the beaker.

This statement indicates that during the mixing of the two liquids, a gas was released and escaped into the environment, leading to a loss of mass in the contained system. This does not violate the law of conservation of mass, which states that matter cannot be created or destroyed in a closed system. The discrepancy in mass occurs because the system was not closed when the gas escaped.