Tag: let's play with water

Questions Related to let's play with water

Different samples of water were found to contain hydrogen and oxygen in the ratio of 1 : 8. This shows the law of:

  1. multiple proportions

  2. constant proportions

  3. reciprocal proportions

  4. conservation of mass


Correct Option: B
Explanation:

Law of Constant proportion states that a chemical compound always contains same elements combined together in the same proportion by mass.

All samples of carbon dioxide contain carbon and oxygen in the mass ratio of $3 : 8$. This is in agreement with the law of :

  1. conservation of mass

  2. constant proportion

  3. multiple proportions

  4. gaseous volumes


Correct Option: B
Explanation:

LAW OF CONSTANT OR DEFINITE PROPORTION : It was given by Proust.
It states that all chemical compounds are found to have constant composition irrespective of their method of preparation or sources.
THE LAW OF MULTIPLE PROPORTION : It was given by Dalton.
It states that when one element combines with the other element to form two or more different compounds, the mass of one element which combines with a constant mass of the other bear a simple ratio to one another.

Law of constant composition is also called as the law of :

  1. Conservation of mass

  2. Conservation of energy

  3. Multiple proportion

  4. Definite proportion


Correct Option: D
Explanation:

Law of constant composition is also called as the law of Definite proportion which says that the law of constant composition is a chemistry law which states samples of a pure compound always contain the same elements in the same mass proportion.

When hydrogen and oxygen combine to form water, they form:

  1. an unstable compound

  2. a stable mixture

  3. an unstable mixture

  4. an extremely stable compound


Correct Option: D
Explanation:

When hydrogen and oxygen combine to form water, they form water an extremely stable compound. We can say water is a stable compound because tremendous energy is released is a signal that hydrogen and oxygen are very eager to become water or in another way it is very hard to break water molecules apart into its components.

$2H _2+O _2\longrightarrow 2H _2O$

In ammonia, nitrogen and hydrogen always combine in $14:3$ ratio by mass. This is in agreement with :

  1. Law of conservation of mass

  2. Law of definite proportion

  3. Law of multiple proportion

  4. Law of combining volume


Correct Option: B
Explanation:

Law of definite proportion states that elements always combine in the definite ratio by mass. So it is in agreement with the law of definite proportion.

Law of definite proportion does not apply to nitrogen oxide because:

  1. Atomic weight of nitrogen is not conserved

  2. Molecular weight of nitrogen is variable

  3. Equivalent weight of nitrogen is variable

  4. Atomic weight of oxygen is variable


Correct Option: C
Explanation:

Nitrogen forms multiple compounds with oxygen. Hence, we cannot apply the law of definite proportion to nitrogen oxide.

The ratio of mass of nitrogen and oxygen in nitric oxide is in :

  1. $7:16$

  2. $1:8$

  3. $7:8$

  4. $7:15$


Correct Option: C
Explanation:

Formula of Nitric oxide is NO. Mass of nitrogen in NO is 14 g. Mass of oxygen is 16. Therefore ratio is $14:16$ i.e $7:8$.

A solution of copper oxide was prepared by heating, igniting and precipitation. Which of the following method will give higher ratio of copper oxide?

  1. Heating

  2. Precipitation

  3. Ignition

  4. All of the above will give the same ratio


Correct Option: D
Explanation:

In a compound the ratio of the atoms or element by mass remains always same irrespective of the source of compound. This means a certain compound always formed by the combination of atoms in same ratio by mass. Hence, copper oxide made from any method will always give the same ratio of copper oxide.

In a compound the ratio of the atoms or element by mass remains always same irrespective of :

  1. temperature

  2. nature of compound

  3. source of compound

  4. size of compound


Correct Option: C
Explanation:

Compounds are formed by the combination of two or more elements. In a compound the ratio of the atoms or element by mass remains always same irrespective of the source of compound. This means a certain compound always formed by the combination of atoms in same ratio by mass. If the ratio of mass of constituent atoms will be altered the new compound is formed.

If the ratio of the atoms by mass is altered then :

  1. new compound formed

  2. same compound are formed

  3. no reaction takes place

  4. state of compound are changed


Correct Option: A
Explanation:

In a compound the ratio of the atoms or element by mass remains always same irrespective of the source of compound. This means a certain compound always formed by the combination of atoms in same ratio by mass. If the ratio of mass of constituent atoms will be altered the new compound is formed.