Tag: in the land of kerala

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Questions Related to in the land of kerala

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

Which of the following compounds are not called Thomas slag?

  1. Calcium silicate

  2. Calcium phosphate

  3. Barium phosphate

  4. Strontium silicate
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
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.
Multiple choice geography in the land of kerala introduction to metallurgy occurrence of metals study of kerala

Composition of azurite mineral is:

  1. $CuCO _3.CuO$
  2. $Cu(HCO _3) _2.Cu(OH) _2$
  3. $2CuCO _3.Cu(OH) _2$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
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 $2CuCO _3.Cu (OH) _2$

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

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

  1. Thomas slag

  2. Used in cement manufacturing

  3. Used in manufacturing of phosphorus fertilizer

  4. Used as a refactory material
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
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.

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

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Which statement is correct?

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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