Question

Meredith mixes together 5 grams of baking soda and 5 grams of vinegar in a test tube that is not sealed. She then weighs the product and finds that it weighs 9 grams. Mathew conducts the same experiment, except in a sealed bag. He finds that 5 grams of baking soda and 5 grams of vinegar will result in 10 grams of product. Which of the following might account for their different findings?
*
1 point
Some of the mass from the test tube was destroyed.
Some of the mass of the reactants was converted to light.
Some of the mass escaped from the test tube as a gas before it was massed.
Some of the mass was created during the reaction between vinegar and baking soda in the bag.

Answer 1

The difference in findings between Meredith and Mathew can be accounted for by the fact that "some of the mass escaped from the test tube as a gas before it was massed."

When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), it produces carbon dioxide gas, water, and sodium acetate. Since Meredith conducted her experiment in an open test tube, the carbon dioxide gas could escape into the air, resulting in a lower final mass of the product. In contrast, Mathew's experiment was conducted in a sealed bag, which would contain all the gases produced during the reaction, leading to a higher final mass of the product.

Therefore, the correct answer is:
**Some of the mass escaped from the test tube as a gas before it was massed.**