Tag: study of kerala

Questions Related to study of kerala

Identify the ore not containing iron.

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

  1. Limonite

  2. Siderite

  3. Carnelite

  4. Chalcopyrites

Show answer
Correct Option: C,D
Explanation:
Limonite, $Fe _2O _3.3H _2O$ and Silderite, $FeCO _3$ are iron ore.

Carnallite is an evaporite mineral, a hydrated potassium magnesium chloride with formula $KMgCl _3.6H _2O$. 

Chalcopyrite is the most important and major source of copper metal. It is widely spread copper–iron sulphide mineral with chemical formula, $CuFeS _2$.

Thus, Carnelite and chalcopyrite are not the ore of iron.

Hence, option C and D are correct.

Flux is used to remove :

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

  1. Tempering

  2. Annealing

  3. Hardening

  4. Remove the gangue

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Correct Option: D
Explanation:

Flux is used to remove the gangue to form easily fusible slag.
$\underset {flux} {SiO _2} +\underset {gangue} {FeO}\rightarrow \underset {slag} {FeSiO _3}$

Which of the following metals are found in native state?


Ag, Pt, C, Si, N, O, Mg, Na, Pb

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

  1. Ag, Pt, C, N, O

  2. Ag, Pt, Mg

  3. Ag, Pt, Pb, Mg

  4. Ag, Pt

Show answer
Correct Option: D
Explanation:

Ag and Pt are found in native (free) state.
Native silver usually occurs associated with coppr and gold, e.g., in alluvial sands.

CO is toxic because it forms complex with _________ in the blood.

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

  1. carbohydrate

  2. protein

  3. haemoglobin

  4. none of these

Show answer
Correct Option: C
Explanation:

Carbon monoxide binds very strongly to the iron in hemoglobin. Once carbon monoxide attaches, it is very difficult to release. While breathing in carbon monoxide, it sticks to your hemoglobin and takes up all of the oxygen-binding sites. Eventually, blood loses all of its ability to transport oxygen and will cause unconsciousness.

During smelting, an additional substance is added which combines with impurities to form a fusible mass. The additional substance is called__________.

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

  1. Flux

  2. Slag

  3. Gangue

  4. Ore

Show answer
Correct Option: A
Explanation:

In the process of smelting, inorganic chlorides, fluorides, limestone and other materials are designated as "fluxes" when added to the contents of a smelting furnace or a cupola for the purpose of purging the metal of chemical impurities such as phosphorus, and of rendering slag more liquid at the smelting temperature.

$SnO _2$ is reduced to metallic Sn on smelting oxide with anthracite and lime. In this, the function of lime is :

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

  1. it acts as a flux

  2. it removes acidic impurities as slag

  3. it removes ,basic impurities as slag

  4. it acts as a slag

Show answer
Correct Option: A,B
Explanation:

In the smelting process the black Sn is mixed with anthracite and little limestone which acts as flux, now this mixture is heated to a degree centigrade of 1200-1300, as a result, $SnO _2$ is reduced to Sn. This crude is having many acid impurities which can be removed as slag.$SnO _2+2C \Rightarrow Sn+2C$.

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

Show answer
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.