Question

Explain the Law of constant proportions
​

Answer 1

Answer:

Hope This Will Help You

Explanation:

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).

The law of constant proportions is often referred to as Proust’s law or as the law of definite proportions. An illustration describing the mass ratio of elements in a few compounds is provided below. The ratio of the number of atoms of each element is provided below the mass ratio. For example, in a nitrogen dioxide (NO2) molecule, the ratio of the number of nitrogen and oxygen atoms is 1:2 but the mass ratio is 14:32 (or 7:16).

Law of Constant Proportions

In the year 1794, the French chemist Joseph Proust formulated the law of constant proportions from his work on sulphides, metallic oxides, and sulfates. This law was met with a lot of opposition in the scientific community in the 18th century. The introduction of Dalton’s atomic theory favoured this law and a relationship between these two concepts was established by the Swedish chemist Jacob Berzelius in the year 1811.

Answer 2

Answer:

The law of constant proportion is also known as the law of definite proportion. This law, which was introduced by Proust, stated that ‘in a compound, the elements are always present in definite proportions by mass’. Thus, according to this law, the elements always combine to form chemical compounds in a definite proportion by mass. In other words the relative ratio in which the elements compounds with each other to form compounds is fixed and definite and does not vary.

For example, pure water obtained from any source (well, river, lake, or sea) and from any country (India, Russia, America, etc.) will always contain two hydrogen atoms and one oxygen atom. Hydrogen and oxygen respectively combine together in the ratio of 1:8 by mass to form water. The ratio by the number of atoms for water will always be H : O = 2 : 1. Thus, 18 g of water contains 2 g of hydrogen and 16 g of oxygen, or the ratio of masses of hydrogen to oxygen will always be 1:8.