Oxidizing and reducing agents (Day 3)

Question 1

What is Oxidizing Agent?

Answer 1

A oxidizing agent oxidizes another reactant and gets reduced.

Question 2

What is a Reducing Agent?

Answer 2

A reducing agent reduces another reactant and gets oxidizes.

Question 3

What is Corrosion?

Answer 3

Corrosion is an oxidation-reduction reaction between a metal and substances in the environment.
Corrosion costs billions of dollars due to society every year due to replacing equipment, loss of production due to damage to equipment, extra efforts made to minimize corrosion, extra care and cleaning of material to restore appearance and inspections to make sure equipment is not harmed by corrosion.

Question 4

What are some of the ways to slow down corrosion?

Answer 4

1. Painting - Is the most common way. Paint forms a seal which does not allow oxygen and moisture from the air to react with the metal. This prevents corrosion.
2. Adding enamel - Is another way to top corrosion. Enamel is a hard, shiny and unreactive type of glass that is melted onto a metal surface.
3. Using a metal lower down in series as coating - Iron is more easily oxidized than tin. To slow down corrosion, iron or steel cans are coated with tin. Tin is less reactive and oxidizes slowly and the can does not corrode easily.
4. Surface metal oxides - A better way than lining steel cans with tin, is using aluminum cans. Aluminum is more reactive than iron, but aluminum does not corrode as quickly. Aluminum reacts with oxygen to form aluminum oxide. This layer is tough does not flake off easily. It provides a coating to prevent the aluminum beneath.
5. Galvanization - This is covering iron or steel with a layer of zinc. The zinc acts as a protective layer. If the layer is broken, the iron is still protected, since zinc is more easily oxidized than iron. Until all the zinc is oxidized the iron is protected.
6. Sacrificial metals - Magnesium and zinc are used as sacrificial metals. They are destroyed to protect iron. They are used to protect ships and underground pipelines. The more reactive metals are attached to portions of they objects they are intended to protect. This is different from galvanization, which covers the entire surface of iron, Once they are destroyed the magnesium and zinc have to be replaced.
7. Accidental Corrosion - Sometimes corrosion occurs by accident. A person trying to do his own plumbing might connect a copper pipe to an iron pipe by mistake. A redox reaction occurs and since iron is more reactive than copper, it gets oxidized and forms. After sometime the pipe will leak and water will be red.

Question 5

What is Rust?

Answer 5

Rust is a type of corrosion that involves oxidation of iron metal. Rust is a red, flaky material that forms on iron and steel.