Question
Kevin's Experiment
Kevin's Experiment
Kevin sets up a simple science experiment. He fills a test tube with sodium hydroxide solution. Then, he ties a string around the test tube and pulls it tight under the stopper of a flask containing a copper sulfate solution. When Kevin releases the string, the test tube falls into the copper sulfate solution and the two solutions combine. A diagram of the setup is shown.

Constructed Response Question
Explain a reason Kevin used a stopper in his experimental setup AND what could happen to the mass of the products of this reaction if the stopper were not used.
Kevin's Experiment
Kevin sets up a simple science experiment. He fills a test tube with sodium hydroxide solution. Then, he ties a string around the test tube and pulls it tight under the stopper of a flask containing a copper sulfate solution. When Kevin releases the string, the test tube falls into the copper sulfate solution and the two solutions combine. A diagram of the setup is shown.

Constructed Response Question
Explain a reason Kevin used a stopper in his experimental setup AND what could happen to the mass of the products of this reaction if the stopper were not used.
Answers
GPT-4o mini
Kevin used a stopper in his experimental setup to prevent the copper sulfate solution from escaping or spilling out of the flask before the sodium hydroxide solution from the test tube was released. The stopper ensures that the reaction takes place in a controlled environment, allowing Kevin to accurately observe and measure the effects of the chemical reaction without any loss of materials. This is particularly important for safety, as the reaction between sodium hydroxide (a strong base) and copper sulfate (which contains copper ions) can produce heat and other products that should be contained within the flask.
If the stopper were not used, there could be a change in mass of the products of the reaction. Specifically, if the copper sulfate solution were to leak out before the reaction occurred, the total mass of the reactants would decrease, leading to a lower total mass for the final products. Additionally, any gases that might form during the reaction (if any) could escape into the air, further reducing the overall mass of the products measured. In an experiment where mass conservation is crucial, not using the stopper would undermine the accuracy of Kevin's results, leading to misleading conclusions about the reaction's outcomes.
If the stopper were not used, there could be a change in mass of the products of the reaction. Specifically, if the copper sulfate solution were to leak out before the reaction occurred, the total mass of the reactants would decrease, leading to a lower total mass for the final products. Additionally, any gases that might form during the reaction (if any) could escape into the air, further reducing the overall mass of the products measured. In an experiment where mass conservation is crucial, not using the stopper would undermine the accuracy of Kevin's results, leading to misleading conclusions about the reaction's outcomes.