Question

clue 5 detective: all detectives
evidence: investigators noticed a burn mark on the table and weighed the products. in the open lab - room, the reaction started with 100 g of chemicals but only 95 g of products were collected.
task: decide whether this was an open or closed system. explain why some of the mass might appear to be missing.
question: how does the difference between open and closed systems help investigators explain why the law of conservation of mass still holds true in this case?

Explanation:

Step1: Define open and closed systems

In an open system, matter and energy can be exchanged with the surroundings. In a closed system, only energy can be exchanged, not matter.

Step2: Analyze the situation

The reaction in the open - lab room is an open system. Gases could escape during the reaction. So some of the mass might seem 'missing' as products in gaseous form could have left the system.

Step3: Discuss conservation of mass

The law of conservation of mass still holds true in this case. In a closed system, if we were to perform the same reaction, we could account for all the mass because no matter would escape. In the open - system lab room, we just couldn't measure the mass of the gaseous products that escaped.

Answer:

1. It was an open system. In an open system, matter can be exchanged with the surroundings. During the reaction, some of the products in gaseous form could have escaped, making it seem like some of the mass is 'missing'.
2. The law of conservation of mass still holds true. In a closed - system reaction, all the mass of reactants would be accounted for in the products (including gaseous products if we measure them). In an open system like the one in the lab room, we are unable to measure the mass of the gases that escape into the surroundings, but mass is still conserved in the overall chemical process.