Question

tablet 25
water 10
baggie 4
total 39\ttotal 38
matt and juan are studying chemical reactions and the law of conservation of matter in science. each lab group conducted an experiment to verify the law. the boys materials: antacid tablet, water, and a zip lock baggie. they found the mass of all the materials and recorded the mass in grams in the table as well, then calculated the total mass of the system. matt placed the tablet in the baggie and then juan poured in the water. the boys closed the baggie waited until the tablet disappeared. when the reaction was completed, they found the mass of the system again. note their results in the data table. elaborate on the most logical reason why the data did not support the law of conservation of matter.
a the boys did not know how to use the balance properly
b the reaction produced gas bubbles and they have no mass
c some of the water evaporated and could not be massed as a product in the reaction

Explanation:

• Option A: If they didn't use the balance properly, it's less likely to be the main reason for a consistent difference (mass decreased). The law of conservation of matter failure here is more about a physical/chemical process.
• Option B: Gases do have mass, so this is incorrect.
• Option C: When the antacid tablet reacts with water, it produces gas, but also, if the baggie isn't completely sealed or there's evaporation, but more likely, during the reaction, if the baggie wasn't airtight, some gas (or water vapor) could escape, but also, the reaction of antacid (like sodium bicarbonate and acid in tablet) produces CO₂ gas. If the baggie was not fully sealed, the gas could escape, but also, water evaporation could occur. However, the key is that in the law of conservation of matter, the total mass of reactants and products should be equal. If some water evaporated (turned to vapor and maybe escaped the system), then the mass of the products (remaining water, tablet residue, baggie) would be less than the reactants. So this is a logical reason. (Note: The original options might have a typo, but among the given, C is the most logical as gases have mass (so B is wrong), A is unlikely for a systematic error, and C explains mass loss due to evaporation (or gas escape, but the option says water evaporated).)

Answer:

C. Some of the water evaporated and could not be massed as a product in the reaction