What does the Law of Definite Proportions claim?

What does the Law of Definite Proportions claim?

• A. A chemical compound always contains the same mass of elements
• B. A chemical compound can vary in mass depending on the source
• C. A chemical compound always contains the same proportion of elements by mass, irrespective of its source
• D. The composition of elements in a compound can change with temperature

Answer: (C)

The Law of Definite Proportions states that a chemical compound always contains the same proportion of elements by mass, regardless of its source. This principle emphasizes the consistency of chemical composition in compounds; for example, water (H₂O) will always be made up of exactly two hydrogen atoms and one oxygen atom, making the mass ratio of hydrogen to oxygen constant, which is approximately 1:8 by mass. This consistency is fundamental to chemical science, as it reinforces the idea that compounds have fixed compositions that do not change even if the compound is obtained from different sources or formed under different conditions. The other options do not align with this law. One option incorrectly suggests that a compound's mass can vary based on its source, which contradicts the principle of fixed proportions. Another proposes that the composition can change with temperature, which is also not true for definite compounds. Overall, the law is foundational in understanding chemical compounds and their consistent behavior in defined proportions.

The Law of Definite Proportions states that a chemical compound always contains the same proportion of elements by mass, regardless of its source. This principle emphasizes the consistency of chemical composition in compounds; for example, water (H₂O) will always be made up of exactly two hydrogen atoms and one oxygen atom, making the mass ratio of hydrogen to oxygen constant, which is approximately 1:8 by mass. This consistency is fundamental to chemical science, as it reinforces the idea that compounds have fixed compositions that do not change even if the compound is obtained from different sources or formed under different conditions.

The other options do not align with this law. One option incorrectly suggests that a compound's mass can vary based on its source, which contradicts the principle of fixed proportions. Another proposes that the composition can change with temperature, which is also not true for definite compounds. Overall, the law is foundational in understanding chemical compounds and their consistent behavior in defined proportions.