Transition metals/Extracting metals Flashcards
(19 cards)
List the typical properties of transition metals and their compounds.
Properties of Transition Metals:
High melting and boiling points
- (Except mercury, which is liquid at room temperature)
High density
- Much denser than Group 1 metals (e.g. iron vs. sodium)
Good conductors
- Of both heat and electricity
Hard and strong
- Less reactive than alkali metals; used in construction and tools
Malleable and ductile
- Can be shaped and drawn into wires easily
Properties of Transition metal compounds:
- Form coloured compounds
- Can have more that one ion
- Act as catalysts
- Form complex ions
Why is mercury not a typical transition metal?
- It is liquid at rooms temperature.
- It does not form compounds with variable oxidation states as readily.
- It has a weaker metallic bonding.
Describe how the properties of Group 1 metals compare with transition metals.
Density:
- Group 1 metals have low densities
- Transition metals have high density
Melting and boiling points:
- Group 1 metals have low melting and boiling points.
- Transition metals have high melting and boiling points.
Hardness:
- Group 1 metals are soft as they can be cut with a knife.
- Transition metals are hard and strong.
Reactivity:
- Group 1 metals are very reactive ( especially with water and oxygen)
- Transition metals are less reactive.
Reaction with water:
- vigorous (forms hydroxide and hydrogen gas)
- much slower (if at all)
Electrical conductivity:
- Both have good conductivity with electric.
Oxidation states:
- Group 1 metals are always +1
- Variables
Compound colours:
- Group 1 metals usually produce white or colourless compounds.
- Transition metals produce coloured compounnds.
Catalytic Properties
- Group 1 are not known as catalysts
- Transition metals many act as catalysts.
Interpret the formula and names of familiar transition metal compounds.
As Catalysts:
- They speed up chemical reactions without being used up.
- They often have variable oxidation states, allowing them to transfer electrons easily in redox reactions.
In Coloured Compounds and Pigments:
- Transition metals form coloured ions due to electron transitions within d-orbitals.
- This makes them useful in dyes, paints, and ceramics.
In Structural and Electrical Applications:
- Transition metals are strong, hard, dense, and have high melting points.
- They are good conductors of electricity and heat, making them useful in wiring and industrial parts.
Suggest why group 1 metals have different properties compared to transition metals.
- Electron Configuration Differences
- Bonding Strength and Atomic Structure
- Reactivity Differences
- Oxidation States
- Compound Colour and Catalytic Activity
Define oxidation and reduction in terms of oxygen.
Oxidation: Gain of oxygen by a substance
Reduction: Loss of oxidation by a substance
Describe how metals can be extracted.
- Use reduction with carbon or hydrogen
- Use electrolysis
- Phytomining
- Bioleaching
Identify species that are being oxidised and reduced in a chemical reaction
Look at what happens to each element in the reaction:
- If it loses electrons, it is oxidised.
- If it gains electrons, it is reduced.
Explain why some metals are found uncombined in the Earth’s crust .
The main reason is low reactivity.
Unreactive metals found uncombined include Gold, silver and platinum.
Explain how carbon or hydrogen can be used to reduce an ore.
Carbon:
- Carbon is commonly used to extract metals less reactive than carbon from their oxides.
- The carbon displaces the metal from its oxide by removing the oxygen.
Hydrogen:
- Hydrogen can also be used as a reducing agent.
- It works in a similar way to carbon: it removes oxygen from the metal oxide.
What is meant by the extraction of metals?
Removal of a metal from its ore
Ore = a naturally occurring rock containing metal compounds
Usually involves separating the metal from oxygen or sulphur
How are metals more reactive than carbon extracted?
By electrolysis of molten compounds
Requires large amounts of electricity
Used for aluminium, sodium, calcium
How are metals less reactive than carbon extracted?
By reduction using carbon
Carbon removes oxygen from the metal oxide
Used for iron, zinc, tin
Why can gold and platinum be found native (uncombined)?
They are very unreactive
Found in pure form in the Earth’s crust
Do not need to be extracted from compounds
What are the disadvantages of carbon reduction?
Only works for metals less reactive than carbon
Releases carbon dioxide → contributes to climate change
What are the advantages of carbon reduction?
Cheaper than electrolysis
Uses coke/charcoal (inexpensive)
Common method for industrial extraction
Q: What are the advantages of electrolysis?
Works for very reactive metals
Produces very pure metal
Allows control over the purity and composition
What are the disadvantages of electrolysis?
Requires a lot of energy
Very expensive
High carbon footprint (unless powered by renewables)
What environmental impacts are caused by metal extraction?
Habitat destruction from mining
Air and water pollution
Greenhouse gas emissions from energy use
Waste materials and toxic by-products
