General Metallurgy(10.1)

Question 1

What are the physical states of metals at room temperature?

Answer 1

They are solids at room temperature (Exception: mercury)

Metals exist primarily in solid form, with mercury being a notable exception as it is liquid at room temperature.

Question 2

In what physical states do non-metals exist?

Answer 2

They exist in all three states: solid, liquid, and gas

Non-metals can be found as solids (like sulfur), liquids (like bromine), and gases (like oxygen).

Question 3

How do metals typically conduct heat and electricity?

Answer 3

They are good conductors of heat and electricity (Exception: lead)

Most metals have high electrical and thermal conductivity, with lead being a poor conductor.

Question 4

What is a common property of non-metals regarding conductivity?

Answer 4

They are non-conductors of heat and electricity (Exception: graphite)

Graphite is a notable non-metal that can conduct electricity due to its structure.

Question 5

What is the typical melting and boiling point of metals?

Answer 5

They have generally high melting and boiling points (Exception: alkali metals)

Alkali metals, such as lithium and sodium, have lower melting and boiling points compared to other metals.

Question 6

What is a defining characteristic of non-metals in terms of melting and boiling points?

Answer 6

They have low melting and boiling points (Exception: diamond)

Diamond, a form of carbon, is an exception as it has an extremely high melting point.

Question 7

What does it mean for metals to be malleable and ductile?

Answer 7

They can be beaten into thin sheets (malleable) and stretched into long wires (ductile)

Malleability and ductility are key properties that allow metals to be shaped and formed.

Question 8

How do non-metals behave under stress?

Answer 8

They are brittle

Non-metals tend to break or shatter when subjected to stress rather than deforming.

Question 9

What is the ionization energy trend between metals and non-metals?

Answer 9

Metals have low ionization energy, while non-metals have high ionization energy

This trend reflects the tendency of metals to lose electrons and non-metals to gain them.

Question 10

What type of bond do metals generally form?

Answer 10

They form ionic bonds generally

Ionic bonds typically occur between metals and non-metals, where metals lose electrons.

Question 11

What is the typical oxide formed by metals?

Answer 11

They form basic oxides usually

Basic oxides can react with acids to form salts and water.

Question 12

What type of oxides do non-metals typically form?

Answer 12

Their oxides are acidic or neutral

Non-metal oxides can react with bases and often exhibit acidic properties.

Question 13

What is the occurrence of metals in a native state?

Answer 13

Native or free state: Not affected by components of atmosphere like air, moisture, CO2

Metals like gold and platinum can exist in their pure form without reacting with environmental elements.

Question 14

What defines a mineral?

Answer 14

All substances found in nature with metal in them are called minerals

Examples include various ores like cuprite and malachite.

Question 15

What is an ore?

Answer 15

The mineral from which metal can be extracted in a commercially viable way

Ores must have high metal content and be easy to process.

Question 16

What is pyrometallurgy?

Answer 16

The process of extracting metal by chemical reduction of ore at high temperature

Metals like iron and copper are commonly extracted using pyrometallurgy.

Question 17

What is electrometallurgy?

Answer 17

The process of extracting metal by electrolysis of its ore in molten state

Reactive metals like sodium and potassium are extracted using this method.

Question 18

What is hydrometallurgy?

Answer 18

The process of extracting metal by dissolving the ore in water and precipitating the metal

This method is often used for metals like silver and gold.

Question 19

What is an alloy?

Answer 19

A homogenous mixture of metal with other metals or non-metals

Alloys often exhibit enhanced properties compared to their constituent metals.

Question 20

What are ferrous alloys?

Answer 20

Alloys of iron with other metals or non-metals

Examples include steel and stainless steel.

Question 21

What are non-ferrous alloys?

Answer 21

Alloys of metals other than iron

Examples include brass and bronze.

Question 22

What is the significance of alloy formation?

Answer 22

To increase hardness, improve color, lower melting point, change reactivity, and prevent corrosion

Stainless steel is an example of an alloy that resists rust.

Question 23

What are the steps in metallurgical operation?

Answer 23

Crushing and grinding, ore dressing, calcination, roasting, reduction of ore

Each step is crucial for effective extraction and processing of metals.

Question 24

What is the froth flotation process?

Answer 24

A method based on preferential wetting of ore and impurities by immiscible liquids

This method is commonly used for concentrating sulphide ores.

Question 25

What is calcination?

Answer 25

Heating concentrated ore below its melting point in absence or limited air ## Footnote Calcination is used mainly for ores containing oxygen, like carbonates.

Question 26

What is roasting?

Answer 26

Heating concentrated ore in excess air to oxidize the ore ## Footnote Roasting is mainly applied to sulphide ores.

Question 27

What is smelting?

Answer 27

Reduction of oxide ore into metal by heating with carbon at high temperature ## Footnote Smelting is a key step in the extraction of many metals.

Question 28

What is a flux in metallurgy?

Answer 28

A chemical compound added to the ore during smelting to convert refractory impurities ## Footnote Flux helps in forming slag, which is easily fusible.

Question 29

What is the thermite process?

Answer 29

A reduction process using aluminum to extract metals with high affinity for oxygen ## Footnote This method is used for metals like chromium and manganese.

Question 30

What initiates the reduction process in the aluminothermic process?

Answer 30

The heat generated by burning magnesium ## Footnote This reaction is exothermic, maintaining the heat required for further reduction.

Question 31

What is the general reaction in the aluminothermic process?

Answer 31

Metal oxide + Al → Metal + Al2O3 + heat ## Footnote Examples include: Cr2O3 + Al → Cr + Al2O3 + heat.

Question 32

What is electrolytic reduction?

Answer 32

A method for extracting reactive metals like Na, K, Mg, Ca, Al through electrolysis ## Footnote It is applied when metals cannot be reduced by chemical methods due to high reactivity.

Question 33

What is the process for extracting sodium in the Down’s process?

Answer 33

Electrolysis of molten NaCl between graphite anode and iron cathode ## Footnote The reaction involves NaCl ⇄ Na+ + Cl-.

Question 34

What method is used for the extraction of less reactive metals like silver and gold?

Answer 34

Metal precipitation ## Footnote This is an example of hydrometallurgy.

Question 35

What is the overall reaction for extracting silver from argentite ore?

Answer 35

Ag2S + NaCN → Na[Ag(CN)2] + Na2S ## Footnote Followed by precipitation: Na[Ag(CN)2] + Zn → Ag + Na2[Zn(CN)4].

Question 36

What types of impurities may remain after the reduction of ore?

Answer 36

* Other metals * Unreduced oxide or sulphide * Dissolved non-metals * Residual flux, slag ## Footnote These impurities vary based on the nature of the metal.

Question 37

What is the distillation method based on?

Answer 37

Difference of boiling points between the metal and impurities ## Footnote Applied for volatile or low boiling metals like Zn, Hg, Cd.

Question 38

What is liquation based on?

Answer 38

Difference of melting points between metal and impurities ## Footnote Used for purifying metals like tin and lead.

Question 39

What does the poling method involve?

Answer 39

Stirring molten metal with poles of green wood to reduce oxides or sulfides ## Footnote Used for purifying metals like copper and tin.

Question 40

What is electrolytic refining?

Answer 40

A method where impure metal is made anode and pure metal is cathode in an aqueous solution ## Footnote Metals like Cu, Zn, Pb, Ag are purified by this method.

Question 41

What is zone refining used for?

Answer 41

Achieving high purity of metals ## Footnote Impurities are more soluble in liquid metal than in solid.

Question 42

Which method is used to concentrate copper pyrite?

Answer 42

Froth flotation ## Footnote The principle is based on density difference.

Question 43

What is the flux added to remove impurities in the smelting of haematite?

Answer 43

CaCO3 ## Footnote It helps remove SiO2 impurities.

Question 44

What is the reducing agent used in the smelting of haematite?

Answer 44

CO ## Footnote Carbon monoxide is used in the reduction process.

Question 45

What is an example of hydrometallurgy?

Answer 45

Gold extraction by leaching with KCN followed by precipitation with Zn ## Footnote This process involves dissolving gold in a cyanide solution.

Question 46

Which property does not represent a metal?

Answer 46

Formation of allotropes ## Footnote Metals are typically malleable, ductile, and lustrous.

Question 47

What is the main characteristic of the aluminothermic process?

Answer 47

It is an example of pyrometallurgy ## Footnote Involves high-temperature reactions.

Question 48

What is a basic flux example?

Answer 48

CaO ## Footnote Used in metal extraction processes.

Question 49

Which ore is concentrated by magnetic separation?

Answer 49

Haematite ## Footnote This method exploits the magnetic properties of the ore.

Question 50

What is the process of converting zinc blende into its oxide called?

Answer 50

Roasting ## Footnote Involves heating in excess air.

Question 51

What is the purification method for zinc due to its volatility?

Answer 51

Distillation ## Footnote This method is effective for low boiling point metals.

Question 52

What is the extraction method for manganese from Mn3O4?

Answer 52

Aluminothermic process ## Footnote Involves reduction with aluminum at high temperature.

Question 53

Which metal is the most abundant in the earth's crust?

Answer 53

Aluminium ## Footnote It outnumbers other metals in abundance.