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

On the basis of assumptions Dalton explain __________.

  1. Law of definite proportion.

  2. Law of conservation of mass.

  3. Law of combining volume.

  4. Law of reciprocal proportion.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Dalton's atomic theory was primarily used to explain the laws of chemical combination, specifically the Law of Conservation of Mass and the Law of Definite Proportions.

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

Choose the correct option :


Dalton's atomic theory suffered from _________.

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. An atom is the ultimate

  2. Discrete particle of matter

  3. Indivisible particle of matter

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

Law of constant proportion is given by _________.

  1. Thompson

  2. Dalton

  3. Joseph Louis Proust

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
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 $\text{C}$

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

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

  1. hard steel

  2. Brittle steel

  3. hard and brittle steel

  4. hard and tough steel
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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 -

  1. Yellow and green

  2. Brown and blue

  3. Red and greenish-blue

  4. Green and reddish-brown
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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

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

  1. $Zn$, $Cu$
  2. $Fe$, $Cu$
  3. $Sn$, $Zn$
  4. $Al$, $Ag$
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

Permanent magnets can be made from :

  1. hard steel

  2. cobalt steel

  3. stainless steel

  4. wrought iron
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. $FeSiO _3$
  2. $CaSiO _3$
  3. $CaCO _3$
  4. $CaSO _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
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.