Tag: chemistry

Questions Related to chemistry

On the basis of assumptions Dalton explain __________.

chemistry basic concepts of chemistry history of atomic model atomic theory of dalton daltons atomic theory

  1. Law of definite proportion.

  2. Law of conservation of mass.

  3. Law of combining volume.

  4. Law of reciprocal proportion.

Show answer
Correct Option: A

Choose the correct option :


Dalton's atomic theory suffered from _________.

chemistry basic concepts of chemistry history of atomic model atomic theory of dalton daltons atomic theory

  1. Atoms of the same or different types have a strong tendency to combine together to form a new group of atom

  2. The atom can no longer be considered indivisible

  3. Discovery of isotopes indicated that all atoms of the same element are not perfectly identical

  4. All of the above

Show answer
Correct Option: D
Explanation:

Drawbacks of Dalton's atomic theory:

1. The atom is further subdivided into protons, neutrons, electrons.

2. The atoms of same elements are not similar in all aspects. They may vary in mass and density. These are known as isotopes.

3. Atoms of different elements are not different in all aspects. Atoms of different elements that have the same atomic mass are called isobar.

4. According to Dalton atoms of different elements combine in simple whole-number ratio to form compounds. This is not seen in complex organic compounds.

5. This theory fails to explain the existence of allotropes.

On which basis later researches proved that Dalton's atomic theory was not wholly correct :

chemistry basic concepts of chemistry history of atomic model atomic theory of dalton daltons atomic theory

  1. An atom is the ultimate

  2. Discrete particle of matter

  3. Indivisible particle of matter

  4. All of the above

Show answer
Correct Option: D
Explanation:

Drawbacks of Dalton's atomic theory :


1. The atom is further subdivided into protons, neutrons, electrons.


2. The atoms of the same elements are not similar in all aspects. They may vary in mass and density. These are known as isotopes.

3. Atoms of different elements are not different in all aspects. Atoms of different elements that have the same atomic mass are called isobar.

4. According to Dalton atoms of different elements combine in simple whole-number ratio to form compounds. This is not seen in complex organic compounds.

5. This theory fails to explain the existence of allotropes.


Hence the correct option is D.

Law of constant proportion is given by _________.

chemistry basic concepts of chemistry history of atomic model atomic theory of dalton daltons atomic theory

  1. Thompson

  2. Dalton

  3. Joseph Louis Proust

  4. None of these

Show answer
Correct Option: C
Explanation:

Joseph Louis Proust had given the law of constant proportion.


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).

Hence, the correct option is $\text{C}$

Hardened steel on heating in the range of $220^{\circ} C$ to $330^{\circ}C$ and on slow cooling gives :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. hard steel

  2. Brittle steel

  3. hard and brittle steel

  4. hard and tough steel

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Correct Option: D
Explanation:

Hardened steel on heating in the range of $220^{\circ} C$ to $330^{\circ}C$ and on slow cooling gives Hard and tough steel.

Iron filings were added to a solution of copper sulphate. After 10 minutes, it was observed that the blue colour of the solution changes and a layer gets deposited on iron filings. The colour of the solution and that of the coating would, respectively, be -

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Yellow and green

  2. Brown and blue

  3. Red and greenish-blue

  4. Green and reddish-brown

Show answer
Correct Option: D
Explanation:

$Fe+CuSO _4\rightarrow FeSO _4+Cu$
                             Green     Reddish brown
Solution becomes green and reddish brown coating of copper is formed.

In the extraction of iron, the most preferred ores are :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. Hematite and limonite.

  2. Copper pyrites and siderite.

  3. Magnetite and iron pyrites.

  4. Limonite and copper pyrites.

Show answer
Correct Option: A
Explanation:

Hematite and Limonite are the most preferred ores in the extraction of iron.

In which of the following pair of metals, both are commercially extracted from their respective ores by carbon reduction method?

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $Zn$, $Cu$

  2. $Fe$, $Cu$

  3. $Sn$, $Zn$

  4. $Al$, $Ag$

Show answer
Correct Option: C
Explanation:

Tin and zinc are commercially extracted from their respective ores by carbon reduction method.
The oxide ores of tin and zinc are reduced with carbon to form metals.

Permanent magnets can be made from :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. hard steel

  2. cobalt steel

  3. stainless steel

  4. wrought iron

Show answer
Correct Option: D
Explanation:

A permanent magnet is an object made from material that is magnetized and creates its own persistent magnetic field e.g. refrigerator magnet on its door. These are strongly attracted to magnets called as ferromagnetic and are made up of iron,nickel,cobalt and some alloys of rare earth metals.

In the metallurgy of iron using blast furnace, the slag is :

thermodynamic principles of metallurgy general principles and processes of isolation of elements metallurgy chemistry

  1. $FeSiO _3$

  2. $CaSiO _3$

  3. $CaCO _3$

  4. $CaSO _3$

Show answer
Correct Option: B
Explanation:

Slag is a glass like by product left over after a desired metal has been separated from its ore.Slag is usually a mixture of metal oxides and silicon dioxide.These slags can contain metal sulfides and elemental metals.