The Law of Constant Proportions states that:​

Correct option is D

The correct answer is (D) A given chemical compound always contains its component elements in a fixed ratio by mass

Explanation:

The Law of Constant Proportions, also known as Proust's Law, states that a chemical compound always contains the same elements in the same proportion by mass, regardless of the sample size or source of the compound.

Information Booster:

• The law was first proposed by Joseph Proust in 1797.

• This law is fundamental to understanding chemical reactions and the formation of compounds.

• It highlights that the elements in a compound combine in fixed ratios.

• It is applicable to all chemical compounds, including simple and complex compounds.

• The law is an important concept in stoichiometry, which deals with the calculation of reactants and products in chemical reactions.

Additional Information:

• The pressure of a gas is directly proportional to its temperature at constant volume: This describes Gay-Lussac's Law, not the Law of Constant Proportions.

• Energy cannot be created or destroyed, only transformed: This is the law of conservation of energy, related to thermodynamics.

• The total mass of reactants equals the total mass of products in a chemical reaction:This is the law of conservation of mass, formulated by Antoine Lavoisier.