Year 9 - Chemistry - 27-4-15

Homework

   1.     What is Rusting?

   2.    How does Rust prevented? Give three methods.

   3.    What is sacrificial protection of Iron and steel?

   4.    What is Galvanization?

   5.     Find two examples of alloys

           For each give an example of its use and why it is desirable.

          For example

·         Stainless steel

·         Kitchen sinks

·         Does not rust

As an extension you could find out the component elements. For example stainless steel has iron, chromium and nickel in it

   6.          

Imagine you are the designer of a new sports car. The manufacturer wants to use iron for the bodywork because it is quite cheap to manufacture. You would like to have more money to spend on the car (higher budget) and are going to a meeting ask for it.

You need to prepare answers for these questions with reasons.

   a)    Is using iron a good idea?

    b)      What material would you like to use to build the car?

   7.    Define

a) Oxidation

b) Reduction

c) Redox Reaction.

  

   8.     In each of the following equations, indicate the element that has been oxidized and the one that has been reduced.  You should also label the oxidation state of each before and after the process:

a)     2 Na + FeCl₂ à 2 NaCl + Fe

b)    2 C₂H₂ + 5 O₂ à 4 CO₂ + 2 H₂O

c)    2 PbS + 3 O₂ à 2 SO₂ + 2 PbO

d)          2 H₂ + O₂ à 2 H₂O

e)    Cu + HNO₃ à CuNO₃ + H₂

f)    AgNO₃ + Cu à CuNO₃ + Ag