Tag: general principles of metallurgy

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Questions Related to general principles of metallurgy

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

Copper is extracted from the ore copper pyrite by smelting in a blast furnace. The flux used and the slag formed are :

  1. flux $CaO$, slag $CaSiO _3$
  2. flux $SiO _2$, slag $CaSiO _3$
  3. flux $FeO$, slag $FeSiO _3$
  4. flux $SiO _2$,slag $FeSiO _3$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Copper is extracted from the ore copper pyrite by smelting in a blast furnace. The flux used is  $SiO _2$ and slag formed is $FeSiO _3$.

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

Chloroform on reduction with zinc dust and water gives

  1. Methyl chloride

  2. Dichloro methane

  3. Chloro methane

  4. Methane
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$\underset{\displaystyle chloroform}{CHCl _3}\overset{\displaystyle 6[H]; Zn/H _2O}{\underset{\underset {\displaystyle -ZnCl _2}{-HCl}}{\displaystyle \rightarrow}}\underset{\displaystyle methane}{CH _4}$.
Chloroform on reduction with Zn and HCl gives dichloromethane $(CH _2Cl _2)$.

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

Polling process is employed for the removal of:

  1. $Cu _2O\ from \ Cu$
  2. $Al _2O _3\ from\ Al$
  3. $Fe _2O _3\ from\ Fe$

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Polling is a metallurgical method employed in the purification of copper which contains cuprous oxide as an impurity. 

In the past, freshly cut trees were used as wooden poles. The sap in these poles acted as the reducing agent. The heat of the copper makes the pole emit a gas that reduces the cuprous oxide to copper. 

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

When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains:

  1. Sulphides of copper (II) and iron (II)

  2. Sulphides of copper (II) and iron (III)

  3. Sulphides of copper (I) and iron (II)

  4. Sulphides of copper (I) and iron (III).
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Copper matte is a mixture of cuprous sulphide (Cu2S) and ferrous sulphide (FeS). These are sulphides of copper (I) and iron (II).

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

The balance reaction involved during extraction of zinc from its ore, by calcination of zinc ore, is:

  1. $2ZnCO _{3} (s) \xrightarrow{Heat} 2ZnO(s) + CO _{2}(g)$
  2. $ZnCO _{3} (s) \xrightarrow{Heat} ZnO(s) + CO _{2}(g)$
  3. $ZnCO _{3} (s) \xrightarrow{Heat} 2ZnO(s) + CO _{2}(g)$

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Calcination is defined as heating to high temperatures in the presence of air or oxygen. Heating the metal carbonates result in the formation of metal oxides and carbon dioxide.
$ZnC{ O } _{ 3 }(s)\xrightarrow { heat } ZnO(s)+C{ O } _{ 2 }(g)$