Tag: production of metals

Quizzes (5) Questions (161)

Questions Related to production of metals

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Carbon cannot be used to produce magnesium by chemical reduction of $MgO$ because:

  1. carbon is not a powerful reducing agent

  2. magnesium reacts with carbon to form carbides

  3. magnesium is less electropositive than carbon

  4. carbon does not react with magnesium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Magnesium is a very reactive metal. At the high temperatures required for carbon reduction, magnesium reacts with carbon to form magnesium carbide (MgC2), making the reduction process ineffective.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

When $FeCr _2O _4$ (chromite) is reduced with Carbon in an electric-arc furnace:

  1. Cr and $Fe _2O _3$ are formed
  2. Fe and $Cr _2O _3$ are formed

  3. Fe and Cr (ferrochrome) are formed
  4. $FeCrO _4$ is formed
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When chromite $(FeCr _2O _4)$ is reduced with carbon in an electric-arc furnace, ferrochrome (Fe and Cr) is obtained.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Carbon reduction process is not comrnerically applicable for which of the following set of oxides to extract the respective metal?
(I) ZnO  (II)$Fe _2O _3$   (III)$Al _2O _3$  (IV) $SnO _2$  (V) MgO

  1. $ZnO, Fe _2O _3, SnO _2$
  2. $ZnO, SnO _2, MgO$
  3. $MgO, AI _2O _3$
  4. $MgO, SnO _2, Al _2O _3$,
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Carbon reduction process is used to reduce less electropositive metals.
$Mg, Al$ have high electropositivity. Hence, cannot be extracted from oxides through carbon reduction process.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Carbon can be used to reduce the number of oxides and other compounds, and because of the low cost and availability of coke, this method is widely used. But the disadvantages are that:

  1. high temperature is needed, which is expensive

  2. many metals combine with carbon to form carbides

  3. low temperature is needed, which is expensive

  4. many metal combine with carbon and do not form carbides
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

From the following identify the correct ones.

  1. $Fe _2O _3 + 3CO \rightarrow 2Fe + 3CO _2$
  2. $ZnO + C \rightarrow Zn + CO$
  3. $Ca _3(PO _4) _2 + C \rightarrow P$
  4. $PbO + C \rightarrow Pb$
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation

The correct reactions are as follows-

$Fe _2O _3+3CO\longrightarrow 2Fe+3CO _2$ in Blast furnace.
$ZnO+C\longrightarrow Zn+CO$
$PbO+C\longrightarrow Pb$
$ZnO+C$ and $PbO+C$ can be reduced with carbon.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Identify the metal $M$ whose extraction is based on the following reactions:
$MS+2{ O } _{ 2 }\longrightarrow M{ SO } _{ 4 }$
$2MS+3{ O } _{ 2 }\longrightarrow 2MO+2S{ O } _{ 2 }$
$MS+2MO\longrightarrow 3M+S{ O } _{ 2 }$
$MS+M{ SO } _{ 4 }\longrightarrow 2M+2S{ O } _{ 2 }\quad $

  1. magnesium

  2. aluminium

  3. lead

  4. tin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The given roasting and auto-reduction reactions are classic steps in the extraction of lead (Pb) from galena (PbS). Lead sulfide reacts with oxygen to form lead sulfate and lead oxide, which then react further with remaining sulfide to yield molten lead and sulfur dioxide.

Multiple choice chemistry production of metals extraction of metal from concentrated ore basics of metallurgy extraction of metals from ore

Which of the following oxides cannot be reduced to metal by carbon?

  1. $ZnO$
  2. $Al _2O _3$
  3. $CuO$
  4. $CaO$
Reveal answer Fill a bubble to check yourself
B,D Correct answer
Explanation

Generally carbon is more reactive than $Zn$ and $Cu$. Hence, $ZnO$ and $CuO$ can be reduced by carbon leading to the formation of corresponding metals,  but carbon is less reactive than $Ca$ and $Al$, so $CaO$ and $Al _2O _3$ can not be reduced by carbon .