Question

Law of constant proportion is given by _________.

• A. Thompson
• B. Dalton
• C. Joseph Louis Proust
• D. None of these

Answer 1

Answer: (C)

Joseph Louis Proust

Joseph Louis Proust had given the law of constant proportion.

The law of constant proportions states that chemical compounds are made up of elements that are present in a fixed ratio by mass. This implies that any pure sample of a compound, no matter the source, will always consist of the same elements that are present in the same ratio by mass. For example, pure water will always contain hydrogen and oxygen in a fixed mass ratio (a gram of water consists of approximately 0.11 grams of hydrogen and 0.88 grams of oxygen, the ratio is 1:8).

Hence, the correct option is $\text{C}$