Ok when you see an extended response question, think what the marking criteria for the question is and use that to structure your response.
For example, lets look at the 2003 Industrial Chemistry extended response question:
"Assesss how environmental issues have been addressed in an industrial method of production of an acid, and an industrial method of production of a base"(6 marks)
The first thing I do is make a list from 1-6 of the marks that can be awarded for the response. For this question, I would do the following:
1. Environmental Issues for Acid Production
2. How has the issue been addressed (acid)
3. Evaluation of the how effective the environmenal issue has been addressed
4. Environmental Issues for Base Production
5. How has the issue been addressed (base)
6. Evaluation of the how effective the environmenal issue has been addressed
If i responded to this question, I would give focus to the main environmental issue for both processes and mention a less significant issue for both just incase
Always remember to make a strong evaluation for both points, because in the end you are ASSESSING the effectiveness, not describing it.