Required practical: corrosion

Question 1

Step 1

Answer 1

Get 3 test tubes
Place an iron nail in:
One with only distilled water
One with boiled distilled water with oil on top
One with anhydrous calcium chloride powder and a bung

Question 2

What is the role of test tube with only distilled water?

Answer 2

To measure the effect WATER and AIR had on corrosion

Question 3

What is the role of the boiled distilled water and oil test tube?

Answer 3

To measure the effect WATER had on corrosion
Boiling water removes air
Oil prevents air in test tube dissolving into the water

Question 4

What is the role of the test tube with anhydrous calcium chloride powder and bung?

Answer 4

To measure the effect only AIR has on corrosion
Bung prevents MOIST air entering
Powder removes any traces of water in the test tube

Question 5

Step 2

Answer 5

Leave test tubes for a week

Question 6

Step 3

Answer 6

Record results

Question 7

What is the test tube with distilled water results like?

Answer 7

Had air and water in it
So had rust

Question 8

What is the test tube with boiled distilled water and oil results like?

Answer 8

Had water but no air
So had no rust

Question 9

What is the test tube like with a bung and anhydrous calcium chloride powder results like?

Answer 9

Had air but no water
So no rust

Question 10

So what are the conclusions?

Answer 10

Corrosion/rust must require water and oxygen