LAST PAPER ONEEE

Question 1

What is corrosion

Answer 1

The process by which metals are slowly broken down by reacting with substances in the environment

Question 2

What two things are needed for rusting

Answer 2

water oxygen

Question 3

In the rusting example eriment what are in the three test tubes and why

Answer 3

In the first test tube its water and an iron nail, the water is boiled to remove oxygen and oil is put ontop to stop any more oxygen from dissolving in

in the second test tube it’s just oxygen and the nail calcium chloride is put at the bottom to remove any water vapour from the air

in the third test tube it’s oxygen and wyater and the nail rusts

Question 4

What are the two types of methods when dealing with corrosion

Answer 4

Barrier methods
-paint it
-oil or grease it
- electroplating

sacrificaial methods
- adding a more reactive metal to the iron so the more reactive metal will be oxidised instead

Question 5

What uses both methods to prevent rust

Answer 5

galvanising so like coating the object in a layer of zinc, thus acts as a barrier method by forming a protective coating but also as a sacrificial method as the zinc will react with oxygen

Question 6

For a titration practical what are the three colour changes for different indicators

Answer 6

Litmus paper
alkali- acid
blue-red

penolphalin
alkaline-acidic
pink-colourless

methyl orange
alkaline to acidic
yellow to red

Question 7

Why is it important to consider atom economy

Answer 7

1)raw materials are expensive
2) less sustainable/sustainability?
3) waste products can be expensive to get rid of

Question 8

What’s the best solution to increase atom economy

Answer 8

Use a more efficient reaction
find a use for the waste products