53. A pet store worker prepares a saltwater tank for fish by pouring ocean salt into a tank of pure water. How is the mass of the ingredients affected, according to the law of conservation of matter?
Answer: D
The mass of the pure water and salt equals the mass of the saltwater mixture.
According to the law of conservation of matter, the total mass of the ingredients in a closed system remains constant. When the ocean salt is added to the pure water, the combined mass of the salt and water will equal the mass of the resultant saltwater mixture.
A) The mass of the salt equals the mass of the pure water.
This statement is incorrect because it implies that the mass of the salt is equivalent to the mass of the water alone, disregarding the contribution of both components to the final mixture. The law of conservation of matter indicates that the total mass of all substances must be considered.
B) The mass of the salt equals the mass of the saltwater mixture.
This option is incorrect as it suggests that the mass of the salt alone is equal to the mass of the entire saltwater mixture. The mass of the saltwater mixture includes both the mass of the salt and the mass of the water, making this statement false.
C) The mass of the pure water equals the mass of the saltwater mixture.
This statement is inaccurate because it indicates that the mass of the pure water alone is equal to the mass of the saltwater mixture. The mixture's mass must include both the water and the added salt, hence the mass of the pure water cannot equal the mass of the mixture.
D) The mass of the pure water and salt equals the mass of the saltwater mixture.
This statement is correct as it aligns with the law of conservation of matter, which dictates that the total mass of all reactants (in this case, the pure water and the salt) must equal the mass of the products (the saltwater mixture).
Conclusion
The correct answer, D, accurately reflects the principle of conservation of matter, demonstrating that the total mass before and after the addition of salt remains unchanged. Options A, B, and C fail to recognize that both the salt and the water contribute to the total mass of the resulting mixture, making them incorrect in the context of the law being tested.