SC13 Transition Metals, Alloys and Corrosion ✓ Flashcards Preview

Edexcel GCSE Chemistry COPY > SC13 Transition Metals, Alloys and Corrosion ✓ > Flashcards

Flashcards in SC13 Transition Metals, Alloys and Corrosion ✓ Deck (19)
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1

SC13a - Where are Transition Metals found, on the periodic table?

In the middle of the periodic table, between groups 2 and 3

2

SC13a - Describe some typical physical properties of transition metals.

  • Malleable
  • Ductile
  • Lustrous (when polished)
  • Good conductors of heat and electricity
  • High melting points and densities (compared to groups 1 and 2)

3

SC13a - Describe some typical chemical properties of transition metals.

  • Usually form coloured compounds (colour decided by the ion involved e.g. copper forms blue compounds)
  • Chemical catalysts

4

SC13b - What is corrosion?

When a metal continuously oxidises over time becoming weaker

5

SC13b - What are the two requirements for corrosion to occur?

Oxygen (in air typically) and water

6

SC13b - What is rusting?

The corrosion of Iron (or steel)

7

SC13b - What is oxidation in terms of electrons and oxygen?

The loss of electrons and/or the gain of oxygen

8

SC13b - How does sacrificial protection work?

  • A more reactive metal is attached to Iron or Steel.
  • The oxygen and water are going to react with the more reactive metal instead, protecting the iron and steel

9

SC13b - Which metals are typically involved in sacrificial protection?

Zinc or magnesium, protecting iron or steel from rusting

10

SC13b - What makes a metal more or less reactive?

How easily its able to loose its outer shell electrons (this is a combination of how many there are and how far away from the nucleus they are)

11

SC13c - For what two main reasons may a metal be electroplated?

  • To improve its appearance
  • To improve its resistance to corrosion or rusting

12

SC13c - What process is used to electroplate a metal?

Electrolysis

13

SC13c - What is galvanising?

Coating iron or steel with zinc to protect it.

14

SC13c - Which two methods can be used to galvanise an object?

Dipping it in molten zinc or electroplating

15

SC13c - When electroplating, what would you use as the anode and cathode?

  • Cathode will be the object you are plating
  • Anode will be the metal you are plating it with.

16

SC13d - What is an alloy?

A mixture of a metal with one or more other (not necessarily metal) elements

17

SC13d - Why are alloys stronger than pure metals [4 marks]

  • In a pure metal all the atoms are the same size in a regular structure
  • his allows layers to slide over each other easily
  • In an alloy, the atoms are different sizes in an irregular structure
  • This means layers cannot slide over each other as easily

18

SC13e - Name some uses of gold copper and aluminium linked to their properties that suit its use.

Gold:

  • Memory chips - Good conductor of electricity
  • Jewellery - Lustrous

Copper:

  • Wires - Ductile
  • Coins - Cheap and malleable

Aluminium:

  • Overhead cables - Low density

19

SC13e - Name some uses of magnalium, brass and nitinol linked to their properties that suit its use.

Magnalium (Magnesium and aluminium):

  • Lightweight mechanical parts
    • Low density
    • High strength

Brass (Copper and zinc):

  • Plug in points
    • Corrosion resistant
    • Good conductor of electricity

Nitinol (Nickel and Titanium):

  • Braces and glasses frames
    • Shape memory allows it to have 2 shapes depending on pressure or temperature.