Tag: laws of chemical combination

Questions Related to laws of chemical combination

Gases react in a simple whole number ratio of volume

law of reciprocal proportion laws of chemical combination basic concepts of chemistry some basic concepts of chemistry chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

According to Gay-Lussac's Law, the ratio between the volumes of reactants and products can be expressed in simple whole numbers.

Among the following pairs of compounds, the one that illustrates the law of multiple proportions is:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. $NH _{3}$ and $NCl _{3}$

  2. $H _{2}S$ and $SO _{2}$

  3. $CuO$ and $Cu _{2}O$

  4. $CS _{2}$ and $FeSO _{4}$

Show answer
Correct Option: C
Explanation:

According to the concept of law of multiple proportions, if two elements chemically combine to give two or more compounds, then the weight of one element which combines with the fixed weight of the other element in those compound, bear simple multiple ratios to one another.


Hence, $CuO$ and $CU _2O$ form two different compounds in a ratio of 1:2 with the fixed weight of oxygen.

The % composition of four hydrocarbons are as follows:


(i) (ii) (iii) (iv)
%C 75 80 85.7 91.3
%H 25 20 14.3 8.7


The data illustrates the law of:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. constant proportion

  2. conservation of mass

  3. multiple proportion

  4. reciprocal proportion

Show answer
Correct Option: C

The laws of multiple proportion was proposed by :

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. Lavoisier

  2. Dalton

  3. Proust

  4. Gay Lussac

Show answer
Correct Option: B
Explanation:

The British scientist, John Dalton proposed the Law of Multiple Proportion.

The % of hydrogen in water and hydrogen peroxide is $11.2$ % and $5.94$ % respectively. This illustrates the law of:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. constant proportions

  2. conservation of mass

  3. multiple proportions

  4. law of gaseous volume.

Show answer
Correct Option: C
Explanation:

The law of multiple proportions say that if two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers. 

The oxides of nitrogen contain 63.65%, 46.69% and 30.46% of nitrogen by weight, respectively. This data illustrates the law of:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. constant proportions

  2. multiple proportions

  3. reciprocal proportions

  4. conservation of mass

Show answer
Correct Option: B
Explanation:

The law of multiple proportions say that If two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers.
Here, the ratios of oxygen which react with a constant mass of N are $2:3 , 2:1$ and $4:3$ respectively.

The ratio between the different weights of oxygen in different compounds which combine with the same weight of nitrogen ($14$ parts) is $8:16:24:32:40$ or $1:2:3:4:5$.
This is simple whole number which supports the law of:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. conservation of mass

  2. multiple proportion

  3. constant composition

  4. reciprocal proportion

Show answer
Correct Option: B
Explanation:

The answer is multiple proportion.
When two elements combine to from two or more than two compounds, the weights of one of the element which combine with a fixed weight of the other, bear a simple whole number ratio is the law of multiple proportion and the given example supports the law.

Different proportions of oxygen in the various oxides of nitrogen proves the law of:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. equivalent proportions

  2. conservation of mass

  3. multiple proportions

  4. constant proportions

Show answer
Correct Option: C

0.75 mole of solid ‘$A _4$’ and 2 moles of gaseous $O _2$ are heated in a sealed vessel, completely using up the reactants and producing only one compound. It is found that when the temperature is reduced to the initial temperature, the contents of the vessel exhibit a pressure equal to half the original pressure. What conclusions can be drawn from these data the product of the reaction?

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. $A _2O _5$

  2. $A _3O _4$

  3. $A _2O _2$

  4. none of these

Show answer
Correct Option: B
Explanation:
give reaction
$A _4(s) + O _2(g) → A _xO _y$

Applying POAC  law for A atoms,
4 × moles of $A _4  =  x \times moles of A _xO _y$
=> $4 \times 0.75 = x \times  1$
=> x = 3

Applying POAC for O atoms,
$2\times  moles of O _2 = y \times moles of A _xO _y$
=> $2 \times 2 = y \times 1$
=> y = 4

Thus, the formula of the product is $A _3O _4$.

The law of multiple proportion was discovered by:

chemistry basic concepts of chemistry law of multiple proportion law of multiple proportions laws of chemical combination

  1. John Dalton

  2. Richter

  3. Joseph Proust

  4. A. Lavoisier

Show answer
Correct Option: A
Explanation:

John Dalton discovered the law of multiple proportion.