### What Type Of Compounds Are Compared In The Law Of Multiple Proportions?

Law of multiple proportions is concerned with the compounds that are formed from the same elements, as different masses of one element combines with the same relative mass of the other element to form two different compounds.

### How do elements combine to form more than one compound?

Science > Chemistry > Laws of Chemical Combinations > Law of Multiple Proportions – In the previous article, we have studied the law of definite proportions. In this article, we shall study the law of multiple proportions. The law of multiple proportions was given by British scientist John Dalton in 1803. Statement: When two elements combine to form more than one compound, then the different weights of one element combining with a fixed weight of the other element are in simple numerical ratio with each other. Explanation & illustration : This law is applicable to pairs of elements which can form more than one compound. Thus the ratio of different weights of oxygen (32 and 16) combining with a fixed weight of carbon (12) is 32 : 16 i.e.2 :1, which is simple whole number ratio. Illustration 2: Hydrogen and oxygen combine together to give two compounds of water (H 2 O) and hydrogen peroxide (H 2 O 2 ) Thus the ratio of different weights of oxygen (16 and 32) combining with a fixed weight of hydrogen (2) is 16 : 32 i.e.1 :2, which is simple whole number ratio. Illustration 3: Nitrogen combines with oxygen to form the various oxides. Thus the ratio of different weights of oxygen (8, 16, 24, 32, 40) combining with fixed weight of nitrogen (14) is 8 :16 : 24 : 32 : 40 i.e.1:2:3:4:5, which is simple whole number ratio. Limitations of the Law of Multiple Proportions: The existence of isotopes of hydrogen like H 1 or H 2 causes discrepancies similar to that observed in the law of constant proportions.

Hence the same isotope or mixture of isotope should be used throughout the preparation of a series of compounds. Explanation of the Law of Multiple Proportions on the Basis of Dalton’s Atomic Theory: According to Dalton’s atomic theory, compounds are formed by the combination of atoms of different elements in the ratio of simple whole numbers.

Atoms of elements have a fixed weight. Hence, it follows that when elements combine to form more than one compound, the different weights of one which combines with a fixed weight of the other must be in the ratio of simple whole numbers. This explains the law of multiple proportions Numerical Problems: Example – 01: Hydrogen and oxygen are known to form two compounds.

The hydrogen content in one of them is 5.93 % while in other it is 11.2 %. Show that the data illustrate the law of multiple proportions. Solution: Compound – 1: Let us consider 100 g of compound – 1 Mass of hydrogen = 5.93 g Mass of oxygen = 100 g – 5.93 g = 94.06 g Thus, 5.93 g of hydrogen combines with 94.07 g of oxygen.

∴ 1 g of hydrogen combines with 94.07/5.93 = 15.86 g of oxygen. (1) Compound – 2: Let us consider 100 g of compound – 2 Mass of hydrogen = 11.2 g Mass of oxygen = 100 g – 11.2 g = 88.8 g Thus, 11.2 g of hydrogen combines with 88.8 g of oxygen. ∴ 1 g of hydrogen combines with 88.8/11.2 = 7.92 g of oxygen.

(2) From statements (1) and (2), the ratio of different masses of oxygen combining with fixed mass of hydrogen (1 g) is 15.86 : 7.92 i.e.2 : 1, which is simple whole number ratio. Thus, the data illustrate the law of multiple proportions. Example – 02: Carbon and oxygen are known to form two compounds.

The carbon content in one of them is 42.9 % while in other it is 27.3 %. Show that the data illustrate the law of multiple proportions. Solution: Compound – 1: Let us consider 100 g of compound – 1 Mass of carbon = 42.9 g Mass of oxygen = 100 g – 42.9 g = 57.1 g Thus, 42.9 g of carbon combines with 57.1 g of oxygen.

∴ 1 g of carbon combines with 57.1/42.9 = 1.33 g of oxygen. (1) Compound – 2: Let us consider 100 g of compound – 2 Mass of carbon = 27.3 g Mass of oxygen = 100 g – 27.3 g = 72.7 g Thus, 27.3 g of carbon combines with 72.7 g of oxygen. ∴ 1 g of carbon combines with 72.7/27.3 = 2.66 g of oxygen. (2) From statements (1) and (2), the ratio of different masses of oxygen combining with fixed mass of carbon (1 g) is 1.33 : 2.66 i.e.1 : 2, which is simple whole number ratio.

Thus, the data illustrate the law of multiple proportions. Example – 03: A metal forms two oxides. The higher oxide contains 80% of metal.0.72 g of the lower oxide gave 0.8 g of higher oxide when oxidized. Show that the data illustrate the law of multiple proportions.

1. Solution: Higher oxide: Let us consider 100 g of higher oxide Mass of metal = 80 g Mass of oxygen = 100 g – 80 g = 20 g Thus,80 g of metal combines with 20 g of oxygen.
2. 1 g of metal combines with 20/80 = 0.25 g of oxygen.
3. 1) Lower oxide: Mass of lower oxide = 0.72 g Mass of higher oxide = 0.8 g The higher oxide contains 80% of metal.

Mass of metal in higher oxide = 80/100 x 0.8 = 0.64 g Mass of metal in lower oxide = 0.64 g Mass of oxygen on lower oxide = 0.72 – 0.64 = 0.08g Thus 0.64 g of metal combines with 0.08 g of oxygen. ∴ 1 g of carbon combines with 0.125 g of oxygen. Thus the ratio of different masses of oxygen combining with fixed mass of hydrogen (1 g) is 0.25 : 0.125 i.e.2 : 1, which is simple whole number ratio.

 Element % Atomic Mass Atomic Ratio M 72.4 x 72.4/x O 27.6 16 27.6/16

The formula of the first oxide is M 3 O 4, Thus the atomic ratio of M to O in oxide is 3 : 4. Thus the atomic mass of the metal is 56. Second oxide: % of metal = 70 % of oxygen = 100 – 70 = 30

 Element % Atomic Ratio Simplest Ratio Whole Number Ratio M 70 70/56 = 1.25 1.25/1.25 = 1 2 O 30 30/16=1.875 1.875/1.25 = 1.5 3

Thus, the formula of the second oxide is M 2 O 3, In the next article, we shall study the law of reciprocal proportions. Previous Article: The Law of Definite proportions Next Topic: The Law of Reciprocal Proportions

#### How did Dalton deduce the law of multiple proportions?

Definite proportions, Dalton deduced the law of multiple proportions, which stated that when two elements form more than one compound by combining in more than one proportion by weight, the weight of one element in one of the compounds is in simple, integer ratios to its weights in the other

#### Which data illustrate the law of multiple proportions?

Science > Chemistry > Laws of Chemical Combinations > Law of Multiple Proportions – In the previous article, we have studied the law of definite proportions. In this article, we shall study the law of multiple proportions. The law of multiple proportions was given by British scientist John Dalton in 1803. Statement: When two elements combine to form more than one compound, then the different weights of one element combining with a fixed weight of the other element are in simple numerical ratio with each other. Explanation & illustration : This law is applicable to pairs of elements which can form more than one compound. Thus the ratio of different weights of oxygen (32 and 16) combining with a fixed weight of carbon (12) is 32 : 16 i.e.2 :1, which is simple whole number ratio. Illustration 2: Hydrogen and oxygen combine together to give two compounds of water (H 2 O) and hydrogen peroxide (H 2 O 2 ) Thus the ratio of different weights of oxygen (16 and 32) combining with a fixed weight of hydrogen (2) is 16 : 32 i.e.1 :2, which is simple whole number ratio. Illustration 3: Nitrogen combines with oxygen to form the various oxides. Thus the ratio of different weights of oxygen (8, 16, 24, 32, 40) combining with fixed weight of nitrogen (14) is 8 :16 : 24 : 32 : 40 i.e.1:2:3:4:5, which is simple whole number ratio. Limitations of the Law of Multiple Proportions: The existence of isotopes of hydrogen like H 1 or H 2 causes discrepancies similar to that observed in the law of constant proportions.

Hence the same isotope or mixture of isotope should be used throughout the preparation of a series of compounds. Explanation of the Law of Multiple Proportions on the Basis of Dalton’s Atomic Theory: According to Dalton’s atomic theory, compounds are formed by the combination of atoms of different elements in the ratio of simple whole numbers.

Atoms of elements have a fixed weight. Hence, it follows that when elements combine to form more than one compound, the different weights of one which combines with a fixed weight of the other must be in the ratio of simple whole numbers. This explains the law of multiple proportions Numerical Problems: Example – 01: Hydrogen and oxygen are known to form two compounds.

• The hydrogen content in one of them is 5.93 % while in other it is 11.2 %.
• Show that the data illustrate the law of multiple proportions.
• Solution: Compound – 1: Let us consider 100 g of compound – 1 Mass of hydrogen = 5.93 g Mass of oxygen = 100 g – 5.93 g = 94.06 g Thus, 5.93 g of hydrogen combines with 94.07 g of oxygen.

∴ 1 g of hydrogen combines with 94.07/5.93 = 15.86 g of oxygen. (1) Compound – 2: Let us consider 100 g of compound – 2 Mass of hydrogen = 11.2 g Mass of oxygen = 100 g – 11.2 g = 88.8 g Thus, 11.2 g of hydrogen combines with 88.8 g of oxygen. ∴ 1 g of hydrogen combines with 88.8/11.2 = 7.92 g of oxygen.

• 2) From statements (1) and (2), the ratio of different masses of oxygen combining with fixed mass of hydrogen (1 g) is 15.86 : 7.92 i.e.2 : 1, which is simple whole number ratio.
• Thus, the data illustrate the law of multiple proportions.
• Example – 02: Carbon and oxygen are known to form two compounds.

The carbon content in one of them is 42.9 % while in other it is 27.3 %. Show that the data illustrate the law of multiple proportions. Solution: Compound – 1: Let us consider 100 g of compound – 1 Mass of carbon = 42.9 g Mass of oxygen = 100 g – 42.9 g = 57.1 g Thus, 42.9 g of carbon combines with 57.1 g of oxygen.

∴ 1 g of carbon combines with 57.1/42.9 = 1.33 g of oxygen. (1) Compound – 2: Let us consider 100 g of compound – 2 Mass of carbon = 27.3 g Mass of oxygen = 100 g – 27.3 g = 72.7 g Thus, 27.3 g of carbon combines with 72.7 g of oxygen. ∴ 1 g of carbon combines with 72.7/27.3 = 2.66 g of oxygen. (2) From statements (1) and (2), the ratio of different masses of oxygen combining with fixed mass of carbon (1 g) is 1.33 : 2.66 i.e.1 : 2, which is simple whole number ratio.

Thus, the data illustrate the law of multiple proportions. Example – 03: A metal forms two oxides. The higher oxide contains 80% of metal.0.72 g of the lower oxide gave 0.8 g of higher oxide when oxidized. Show that the data illustrate the law of multiple proportions.

Solution: Higher oxide: Let us consider 100 g of higher oxide Mass of metal = 80 g Mass of oxygen = 100 g – 80 g = 20 g Thus,80 g of metal combines with 20 g of oxygen. ∴ 1 g of metal combines with 20/80 = 0.25 g of oxygen. (1) Lower oxide: Mass of lower oxide = 0.72 g Mass of higher oxide = 0.8 g The higher oxide contains 80% of metal.

Mass of metal in higher oxide = 80/100 x 0.8 = 0.64 g Mass of metal in lower oxide = 0.64 g Mass of oxygen on lower oxide = 0.72 – 0.64 = 0.08g Thus 0.64 g of metal combines with 0.08 g of oxygen. ∴ 1 g of carbon combines with 0.125 g of oxygen. Thus the ratio of different masses of oxygen combining with fixed mass of hydrogen (1 g) is 0.25 : 0.125 i.e.2 : 1, which is simple whole number ratio.

 Element % Atomic Mass Atomic Ratio M 72.4 x 72.4/x O 27.6 16 27.6/16

The formula of the first oxide is M 3 O 4, Thus the atomic ratio of M to O in oxide is 3 : 4. Thus the atomic mass of the metal is 56. Second oxide: % of metal = 70 % of oxygen = 100 – 70 = 30

 Element % Atomic Ratio Simplest Ratio Whole Number Ratio M 70 70/56 = 1.25 1.25/1.25 = 1 2 O 30 30/16=1.875 1.875/1.25 = 1.5 3

Thus, the formula of the second oxide is M 2 O 3, In the next article, we shall study the law of reciprocal proportions. Previous Article: The Law of Definite proportions Next Topic: The Law of Reciprocal Proportions

## What is law of multiple proportions in chemistry?

Home Science Chemistry Alternate titles: law of simple multiple proportions law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

For example, there are five distinct oxides of nitrogen, and the weights of oxygen in combination with 14 grams of nitrogen are, in increasing order, 8, 16, 24, 32, and 40 grams, or in a ratio of 1, 2, 3, 4, 5. The law was announced (1803) by the English chemist John Dalton, and its confirmation for a wide range of compounds served as the most powerful argument in support of Dalton’s theory that matter consists of indivisible atoms,

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen,

### How did Dalton deduce the law of multiple proportions?

definite proportions, Dalton deduced the law of multiple proportions, which stated that when two elements form more than one compound by combining in more than one proportion by weight, the weight of one element in one of the compounds is in simple, integer ratios to its weights in the other

## What is Dalton’s Law of compounds?

Home Science Chemistry Alternate titles: law of simple multiple proportions law of multiple proportions, statement that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

• For example, there are five distinct oxides of nitrogen, and the weights of oxygen in combination with 14 grams of nitrogen are, in increasing order, 8, 16, 24, 32, and 40 grams, or in a ratio of 1, 2, 3, 4, 5.
• The law was announced (1803) by the English chemist John Dalton, and its confirmation for a wide range of compounds served as the most powerful argument in support of Dalton’s theory that matter consists of indivisible atoms,

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Erik Gregersen,