L9. Corrosion of metals

• Chem
• Secondary Education

Lesson 9

Corrosion of metals

04-10-2022

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• state the conditions required for the rusting of iron and steel to form hydrated iron(III) oxide
• identify some common methods of preventing the rusting of iron and steel and corrosion of other metals
• describe how these methods work

Success Criteria

Language 

development

• rust
• corrosion
• corrode
• barrier methods
• painting 

Know the keywords

• oiling and greasing
• plastic coatings
• electroplating
• galvanising and sacrificial protection
  

• An in-class interactive, friendly competition which promotes teamwork, critical thinking, investigative learning, and determination.
• The competition can be:

- A quiz bee / quiz show

- Practical work

- Positive behaviour

• A team can earn points by winning or performing well in the activities. A team can get point deductions by not following instructions, messy work table, cheating, etc.

CHEMPETITION !

• As a team, you will be given a copy of the concept notes.
• You have 10 minutes to read, understand, and ask questions to the teacher.
• You will have to return the copies to the teacher. 
• LessonUp will be used as our quiz tool today.
• Only one device is needed per team.
• The team which turns out to be first will be declared the champion for this game.

CHEMPETITION !

• Questions will be based on the readings you did and with the session topic.
• This is a list of the total points you will earn: 

Champion = 5 points

2nd place = 3 points

3rd place = 2 points

non-winners = 1 point

CHEMPETITION !

Preparation 

Time

_____ is a chemical reaction between iron, water, and oxygen to form rust.

1. Rusting
2. Galvanising
3. Sacrificial protection
4. Electroplating

What is the chemical name of rust?

1. iron (III) hydroxide
2. iron (II) oxide
3. iron (II) hydroxide
4. iron (III) oxide

What two conditions must be present for rust to occur?

1. oxygen and carbon
2. oxygen and water
3. oxygen and nitrogen
4. sodium and water

Iron can be prevented from rusting using the _______ series.

1. reaction
2. reactivity
3. metallic
4. sequential

Which of the following is NOT an example of a common barrier that prevent the iron from coming in contact with water and oxygen?

1. grease
2. oil
3. paint
4. zinc

Barrier methods are permanent protection.

1. TRUE
2. FALSE

Based on the investigation results shown in the diagram, which of the following the is MOST successful method?

1. use of oil
2. use of sodium chloride
3. use of water

Why did the nail in water with NO air not show any sign of rust?

During rusting, iron is _________.

1. reduced
2. ionised
3. atomised
4. oxidised

Iron is to rust ; Steel is to corrode.

1. TRUE
2. FALSE

A more reactive metal can be attached to a less reactive metal.

1. TRUE
2. FALSE

Which of the following metals CANNOT be used as a sacrificial protection to iron?

1. aluminium
2. copper
3. magnesium
4. zinc

Which of the following metals corrodes first?

1. aluminium
2. copper
3. magnesium
4. zinc

What two things happen to a more reactive metal if used as sacrificial protection?

1. will be oxidised and corrode last
2. will be oxidised and corrode first
3. will be reduced and corrode last
4. will be reduced and corrode first

How does a more reactive metal protect a less reactive metal?

Zinc is a reactive metal. What happens to its outermost electrons?

1. disappear
2. wasted
3. removed easily
4. given off

_____ is a process where the iron to be protected is coated with a layer of zinc.

1. Coating
2. Rusting
3. Galvanising
4. Electrolysis

What method is used to galvanise iron with zinc?

1. electroplating
2. galvanising
3. dipping it into molten lava
4. electrolyse

What compound is formed when zinc reacts with oxygen and carbon dioxide in the air?

1. zinc carbonate
2. zinc oxide
3. zinc hydroxide
4. zinc plate

• Wednesday - Extraction of iron
• Thursday - NO SCHEDULED CLASS
• Friday - Extraction of aluminium

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