Chemistry 6CH01/01 AS level unit 1

[penelope365]

Hey everyone so im sitting for my chemistry exam in 1 week and a few days and im SOOO SCARED any tips to revise or how to pass this exam?

also i need help in this question http://www.edexcel.com/migrationdoc...2000/June 2011 - QP/6CH01_01_que_20110523.pdf

Question 18 ii) please help im soo confused