Tag: in the land of kerala

Questions Related to in the land of kerala

Which of the following compounds are not called Thomas slag?

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

  1. Calcium silicate

  2. Calcium phosphate

  3. Barium phosphate

  4. Strontium silicate

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Correct Option: A,C,D
Explanation:
Calcium phosphate($Ca _3(PO _4) _2O)$ is called Thomas slag and remaining calcium silicate, barium phosphate and strontium silicate are not Thomas slag.

Hence options A,C & D are correct.

Composition of azurite mineral is:

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

  1. $CuCO _3.CuO$

  2. $Cu(HCO _3) _2.Cu(OH) _2$

  3. $2CuCO _3.Cu(OH) _2$

  4. None of these

Show answer
Correct Option: C
Explanation:

Azurite is one of the basic copper (II) carbonate minerals, the other being bright green malachite. Simple copper carbonate (CuCO3) is not known to exist in nature. Azurite has the formula $Cu(CO _3) _2(OH) _2$ with the copper (II) cations linked to two different anions, carbonate and hydroxide.

Hence the composition of azurite mineral is $2CuCO _3.Cu (OH) _2$

Predict the mode of occurrence of the following metals:

The correct answer is:

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

  1. $Na \rightarrow $ combined form

  2. $Fe \rightarrow $ combined form

  3. $Au \rightarrow $ combined form

  4. none of these

Show answer
Correct Option: A
Explanation:

Sodium (alkali metal) is highly reactive and so, it occurs as a compound i.e. in combined form like NaCl.

${Ca _3(PO _4) _2}$ is :-

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

  1. Thomas slag

  2. Used in cement manufacturing

  3. Used in manufacturing of phosphorus fertilizer

  4. Used as a refactory material

Show answer
Correct Option: A,B,C
Explanation:

${Ca _3(PO _4) _2}$ is called as Thomas slag and is used in cement manufacturing and manufacturing of phosphorus fertilizer,so options A,B & C are correct stetements.
Options A,B & C  are correct.

Silver is found in nature both in native and combined state.  
geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

  1. True

  2. False

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Correct Option: A
Explanation:

Silver is found in nature both in native and combined state. Silver is less reactive than other metals.  Native silver occurs as elongated dendritic coatings or irregular masses.  It may occur alloyed with gold as electrum. It often occurs with silver sulfide and sulfosalt minerals.

The most abundant metal in the earth crust is:

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

  1. Copper

  2. Silver

  3. Aluminium

  4. Silicon

Show answer
Correct Option: C
Explanation:

Aluminum is the most abundant metal in the earth's crust but it is never found free in nature. Silicon is not a metal.

Which statement is correct?

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

  1. Gangues are carefully chosen to combine with the slag present in the ore to produce easily fusible flux to carry away the impurities

  2. Slags are carefully chosen to combine with the flux present in the ore to produce easily fusible gangue to carry away the impurities

  3. Gangues are carefully chosen to combine with the flux present in the ore to produce easily fusible slag to carry away the impurities

  4. Fluxes are carefully chosen to combine with the gangue present in the ore to produce easily fusible slag to carry away the impurities

Show answer
Correct Option: D
Explanation:
Flux: The substance which is added to remove the gangue from the concentrated ore in its molten state is called Flux and the substance formed with flux is called Slag. Hence, fluxes have to be carefully chosen.

Acidic Flux
$SiO _2 + CaO \rightarrow CaSiO _3$
Acidic flux removes basic impurities.

Basic Flux
$SiO _2 + MgO \rightarrow MgSiO _3$
Basic flux removes acidic impurities

Silicon is the main constituent of _______.

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

  1. alloys

  2. rocks

  3. animals

  4. vegetables

Show answer
Correct Option: B
Explanation:

Silicon is the most abundant element in the earth crust. It is found in rocks .


Therefore, the correct answer is $B$

Removal of impurities from ore is known as:

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

  1. Crushing 

  2. Concentration of ore

  3. Washing

  4. Grinding

Show answer
Correct Option: B
Explanation:

The impurities present in the ore is known as gangue. The removal of impurities from the ore is known as concentartion of ore.

During the process of smelting, an additional substance is added which combines with impurities to form a fusible product in metal extraction. It is known as:

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

  1. Slag

  2. Mud

  3. Gangue

  4. Flux

Show answer
Correct Option: D