Tag: occurrence of metals and non metals

Questions Related to occurrence of metals and non metals

Rubies are crystalline forms of_________.

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Copper oxide

  2. Zinc oxide

  3. Aluminium oxide

  4. Iron oxide

Show answer
Correct Option: C
Explanation:

Rubies are crystalline forms of aluminium oxide, which are red in colour due to the presence of chromium as an impurity. 

The carbonate and silicate ore of zinc is called as_________.

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Calamine, pyrite

  2. Calamine, hemimorphite

  3. Hemimorphite, cryolite

  4. Cryolite, calamine

Show answer
Correct Option: B
Explanation:

The carbonate and silicate ore of zinc is called as calamine and hemimorphite respectively.

Which of the following are found as carbonate ore in nature?

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. $Fe$

  2. $Mg$

  3. $Zn$

  4. $Pb$

Show answer
Correct Option: A,B,C
Explanation:

 Carbonate ores are Magnesite $(MgCO _3)$, Dolomite $(CaCO _3MgCO _3)$, Calamine $(ZnCO _3)$, Malachite $(CuCO _3.Cu (OH) _2)$, Siderite $(FeCO _3)$, and Limestone $(CaCO _3)$.

A principal ore of lead is galena $(PbS)$.

 Copper is extracted from sulphide ore using the method:

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Carbon reduction

  2. Carbon monoxide reduction

  3. Auto reduction

  4. None of these

Show answer
Correct Option: C
Explanation:
The copper can be extracted from its sulphide ore by the auto reduction process.
The ore is reduced by heat alone.
 
$Cu _2S + O _2 \rightarrow 2Cu + SO _2$

The copper and the oxygen have been reduced (decrease in oxidation state). The sulphur has been oxidised (increase in oxidation state). The reducing agent is the sulphide ion in the copper(I) sulphide.

Hence, the correct option is $C$

 Which one of the following is not an ore of aluminum?

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Bauxite

  2. Corundum

  3. Epsomite

  4. Cryolite

Show answer
Correct Option: C
Explanation:

The chief ore of aluminium is bauxite $(Al _2O _3.2H _2O)$. Corundum $(Al _2O _3)$ and Cryolite $(Na _3AlF _6)$ are also aluminium ores. Epsomite is a hydrous magnesium sulfate ore with formula $MgSO _4·7H _2O$.

Which of the following are sulphate ores?

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Cinnabar

  2. Gypsum

  3. Galena

  4. Iron pyrite

Show answer
Correct Option: B
Explanation:

Sulphate ores are  Gypsum $(CaSO _4.2H _2O)$, Epsom Salt $(MgSO _4.7H _2O)$, Barytes $(BaSO _4)$ and Anglesite $(PbSO _4)$.

Cinnabar is a mercury sulfide mineral with a chemical composition of $HgS$.
Galena is the natural mineral form of lead(II) sulfide $(PbS)$.
Iron pyrite,  is an iron sulfide with the chemical formula $(FeS _2)$. 

 An alloy which does not contain copper is:

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Bronze

  2. Magnalium

  3. Brass

  4. Bell metal

Show answer
Correct Option: B
Explanation:
Bronze: $Cu+ Sn + Al$
Magnalium: $Al + Mg + Ni$ 
Brass: $Cu + Zn$
Bell metal: $Cu + Sn$ 

Hence, the correct option is $B$

 In the extraction of copper from copper pyrites, iron is removed as:

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. $FeSO _4$

  2. $FeSiO _3$

  3. $Fe3O _4$

  4. $Fe _2O _3$

Show answer
Correct Option: B
Explanation:
The copper ($II$) ions in the copper pyrite are reduced to copper ($I$) sulphide (which is reduced further to copper metal in the final stage).
The iron in the copper pyrite ends up converted into an iron ($II$) silicate slag which is removed.
$CuFeS _2 + SiO _2 + 4O _2 \rightarrow Cu _2S + 2FeSiO _3 + 3SO _2$

Which of the following combination are correct?

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. Fluorspar, $FeCO _3$

  2. Zinc blende, $ZnO$

  3. Magnesite, Oxide ore

  4. Cryolite, Halide ore

Show answer
Correct Option: D
Explanation:
Fluorite (also called fluorspar) is the mineral form of calcium fluoride, $CaF _2$. 
Zinc sulfide $(ZnS)$ is a unique compound that forms two types of crystalline structures. These two polymorphs are wurtzite and zincblende.
 
Magnesite is a mineral with the chemical formula $MgCO _3$ (magnesium carbonate).
Cryolite $(Na _3AlF _6)$, sodium hexafluoroaluminate is a halide ore.

Hence, option $D$ is correct.

Which of the following are found as sulphide ores?

chemistry non-metals introduction to non-metals occurence of metals occurrence of metals and non metals

  1. $Al,\ Hg,\ Pb,\ F$

  2. $Fe,\ Zn,\ Pb$

  3. $Hg,\ Pb,\ Na$

  4. $F,\ Ca,\ Cu,\ Mg$

Show answer
Correct Option: B
Explanation:
The sulfide minerals are a class of minerals containing sulfide $(S^{2−})$ as the major anion. Some sulfide minerals are economically important as metal ores. So the metal ion with this anion should have oxidation state $+2$. 
$Fe, Zn, Pb$ all three are found as  sulfide ores. Ores of these metals are known as:  Pyrite $(FeS _2)$, Sphalerite $(ZnS)$ and Galena $(PbS)$ .