Tag: basics of metallurgy

Questions Related to basics of metallurgy

Can we store copper sulphate in iron container and why?

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. No, because Cu is more reactive than iron

  2. No, because iron is more reactive than copper, therefore reaction will take place.

  3. Yes, because copper is less reactive than iron.

  4. Yes, because copper is more reactive than iron.

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Correct Option: B
Explanation:

$Fe + CuSO _4\rightarrow FeSO _4 + Cu$
Reaction has taken place because Fe is more reactive than Cu, therefore we cannot store.

Bessemerisation is carried out for:

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. Fe, Cu

  2. Cu, Al

  3. Al, Ag

  4. Fe, Al

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Correct Option: A
Explanation:

In this process, air is blown through molten copper matte in a Bessemer converter. Bessemerisation is also used to convert pure iron to steel.

Which process use in smelting during metallurgy of coper

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. Self reduction of copper

  2. $Cu _2S$ is converted into $Cu _2O$

  3. $FeS$ convert into $FeO$

  4. Reduction of $Fe$

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Correct Option: C
Explanation:
Smelting of Cu result in slag formation and matle formation
FeS+Cu2O→FeP+Cu2SFeS+Cu2O→FeP+Cu2S
FCO+SiO2→FesiO3FCO+SiO2→FesiO3(slage)

The metal whose oxide which is amphoteric and is reduced to metal by carbon reduction is :

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. Fe

  2. Cu

  3. Al

  4. Zn

Show answer
Correct Option: D
Explanation:

Reaction:
$ZnO + C \rightarrow Zn + CO$

$2Cu _{2}S + 3O _{2}(g)\xrightarrow {heat} {a} + {b}$

In the reaction above $a$ and $b$ are:

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. $a = 2Cu _{2}O, b = 2SO _{2}$

  2. $a = 4CuO _{2}, b = 2SO _{3}$

  3. $a = 2CuO, b = 4SO _{2}$

  4. $a = 3CuS, b = 2SO _{2}$

Show answer
Correct Option: A
Explanation:

$2Cu _{2}S + 3O _{2} (g)\xrightarrow {\triangle} 2Cu _{2}O + 2SO _{2}(g)$
$2Cu _{2}O + Cu _{2}S\xrightarrow {\triangle} 6Cu(S) + SO _{2}(g)$.

$ZnO(S) + A \rightarrow Zn(s) + B$ :

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. $a = H _{2}, b = O _{2}$

  2. $a = C, b = CO$

  3. $a = S, b = SO _{2}$

  4. $a = N, b = NO$

Show answer
Correct Option: B
Explanation:

$ZnO(s) + C(s) \rightarrow Zn(s) + CO(g)$
Metal oxides are then reduced to the corresponding metals by using suitable reducing agents such as carbon.

The balance reaction involved during extraction of zinc from its ore by roasting of zinc ore :

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. $ZnS (s) + O _{2} \xrightarrow{Heat} ZnO(s) + 2SO _{2}(g)$

  2. $ZnS (s) + 3O _{2} \xrightarrow{Heat} ZnO(s) + 2SO _{2}(g)$

  3. $2ZnS (s) + 3O _{2} \xrightarrow{Heat} 2ZnO(s) + 2SO _{2}(g)$

  4. $ZnS (s) + 3O _{2} \xrightarrow{Heat} 2ZnO(s) + SO _{2}(g)$

Show answer
Correct Option: C
Explanation:

The balanced chemical reaction for extraction of zinc from its ore by roasting of zinc ore is;

$2ZnS(s)+3{ O } _{ 2 }\xrightarrow { heat } 2ZnO(s)+2S{ O } _{ 2 }(g)$

Aluminium and copper are extracted from their oxide and sulphide ores respectively. Which of the following is correct ? 
I. Copper is extracted by the auto reduction of copper oxide by copper sulphide.
II. Aluminium cannot be obtained by chemical reduction due to its strong affinity for oxygen.
III. In electrometallurgy of $Al$, graphite is used as cathode to avoid reoxidation of $Al$ into $Al _2O _3$ by preventing formation of $O _2$.
IV. Sulphide ores of copper are difficult to be reduced than the oxide ores.

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. $I , II ,IV$

  2. $II$ and $III$

  3. $III$

  4. $II$ and $IV$

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Correct Option: A
Explanation:

In the electrometallurgy of $Al$, graphite is used as anode as oxygen being a non-metal is liberated at the anode and the reoxidation of $Al$ into $Al _2O _3$ is avoided.

Which of the following steps correctly depicts the self-reduction of $Cu _2S$ to $Cu$?

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. Roasting

  2. Smelting

  3. Bessemeriztion

  4. Poling

Show answer
Correct Option: C
Explanation:

In the extraction of copper, the self-reduction reaction of Copper taking place in a Bessemer converter is as follows:


$2Cu _{2}S+3O _{2} \rightarrow 2Cu _2O+2SO _{2}$

$Cu _{2}S+2Cu _{2}O\rightarrow 6Cu+SO _{2}$ (self reduction)

Option C is correct.

Which of the following process is not involved in the commercial extraction or pure zinc?

chemistry general principles of metallurgy extraction of copper and zinc extraction of copper and zinc from their oxides basics of metallurgy

  1. Froth floatation

  2. Distillation

  3. Self-reduction

  4. Rapid cooling

Show answer
Correct Option: C
Explanation:

Reduction of zinc oxide is done by carbon, not by self reduction.