Final answer:
To determine the mass of a chemical, weigh the empty container first, then weigh it with the chemical, and subtract the container's weight. This method is critical for chemistry experiments and validates the law of conservation of mass.
Step-by-step explanation:
Understanding Mass in Chemical Experiments and Reactions
To determine the mass of a chemical, a specific weighing process is required in the laboratory. Initially, the tare weight, which is the mass of the empty container such as a weighing boat or watch glass, is recorded. After adding the chemical to this container, the combined mass of the container and chemical is measured. Subtracting the tare weight from the total mass gives the mass of the chemical alone. This method helps ensure precise measurements which are essential in chemistry experiment documentation and analyzing chemical reactions.
In experiments involving chemical reactions, like mixing solutions or a tablet reacting in a balloon, it is crucial to measure the mass of reactants before the reaction and the mass of products afterwards. These mass measurements not only facilitate the balancing of chemical equations but also help verify the law of conservation of mass. The law states that in a closed system, mass is neither created nor destroyed.
Calibrated balances are used in the lab to measure mass accurately. The mass balance technique demonstrates the subtle differences between mass and weight, the former being a measure of matter, while the latter is the force exerted due to gravity. On Earth, a balance can measure weight but is often calibrated to indicate mass—calibrations that would differ in an environment with different gravity, like the Moon.