Tag: in the land of kerala

Questions Related to in the land of kerala

Which of the following is NOT calcination?

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. $Fe(OH) _3.xH _2O\rightarrow Fe _2O _3+H _2O$

  2. $CuCO _3.Cu(OH) _2\rightarrow^ 2CuO+CO _2+H _2O$

  3. $CaCO _3\rightarrow^ CaO+CO _2$

  4. $(NH _4) _2CO _3\rightarrow^ 2NH _3+CO _2+H _2O$

Show answer
Correct Option: D
Explanation:

Calcination is a process of heating to high temperature in air or oxygen, however calcination is also used to mean a thermal treatment process in the absence or limited supply of air or oxygen.

$(NH _4) _2CO _3$ is not an ore.so, it do not undergo calcination.

Which of the following element is found in its native state?

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. Silver

  2. Gold

  3. Sodium

  4. Both (A) and (B)

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Correct Option: D
Explanation:

Silver and Gold occur in native state (free state). 

 
These elements have very low reactivity and are not attacked by oxygen or air, moisture, carbon dioxide or other non metals.

In the extraction of iron slag, which of the following is formed during extraction of iron?

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. $Fe _3C$

  2. $FeSiO _3$

  3. $MgSiO _3$

  4. $CaSiO _3$

Show answer
Correct Option: D
Explanation:

Reaction to form slag
$CaO+SiO _2\rightarrow CaSiO _3$ (slag)

Which of the following statements is correct regarding the slag formation during extraction of a metal like copper or iron?

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. The slag is lighter and lower melting than the metal.

  2. The slag is heavier and lower melting than the metal.

  3. The slag is lighter and higher melting than the metal.

  4. The slag is heavier and higher melting than the metal.

Show answer
Correct Option: A
Explanation:

Slag formed in extraction of metals are lighter and having low melting point than metal so they generally appear in upper layer of solutions.

The combined state of metals are called:

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. Mineral

  2. Gangue

  3. Flux

  4. Native form

Show answer
Correct Option: B
Explanation:

The metal found in nature occur in the free or combined state it is generally known as pure metals. A native metal is a metal found in metallic state naturally.  It can be in the pure form or in the form of an alloy.


$Mineral:$  Minerals are substances that are formed naturally in the earth.  Minerals are usually solid, inorganic, have a crystal structure, and are formed naturally by geological process.


$Gangue:$ It is sand, rock and other impurities surrounding the minerals of interest in an ore. It is the combined state of the metal.

$Flux:$ It is a chemical cleaning, flowing or purifying agent.  It is the substance added to the molten metals to bond with impurities that can be removed.

$Native form:$ Native element, any number of chemical elements that may occur in nature uncombined with other elements.


Hence, the correct option is B.

Which is not a step of metallurgy ? 

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. Reduction

  2. Roasting

  3. Corrosion

  4. Concentration of ore

Show answer
Correct Option: C

Sulphide ores are common for metals:

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. Ag, Cu and Pb

  2. Ag, Cu and Sn

  3. Ag, Mg and Pb

  4. none

Show answer
Correct Option: A
Explanation:

  1. Argentite $Ag _2S$
  2.  Galena $PbS$
  3.  Chalcocite $Cu _2S$
  4.  Copper pyrite (chalco pyrite)$ [CuFeS _2]$
  5.  Cassiiterite $SnO _2$
  6.  Dolomite  [$ Ca Mg (CO _3) _2$]
  7.  Bauxite $Al(OH) _3$

∴ Sulphide containing ores are$ Ag, Cu, Pb.$


Option A is correct.

Which of following metal is extracted by electrometallurgical method-

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. $Cu$

  2. $Fe$

  3. $Na$

  4. $Ag$

Show answer
Correct Option: A,C
Explanation:

electrometallurgical method is used for the extraction of metals which are reactive in nature.

example. sodium,copper,aluminium and many more.

The pair that does NOT required calcination is :

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. ZnO and $Fe _{2}O _{3}.xH _{2}O$

  2. $Fe _{2}O _{3}$ and $CaCO _{3}.MgCO _{3}$

  3. $ZnCO _{3}$

  4. ZnO and MgO

Show answer
Correct Option: D

Which of the following is a basic carbonate mineral?
(i) Malachite  (ii) Dolomite  (iii) Azurite  (iv) Magnesite

geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. (i), (iii) and (iv)

  2. (II), (iii) and (iv)

  3. (i) and (iv)

  4. (iii) and (iv)

Show answer
Correct Option: B