The course is made up of two papers which are examined at the end of year 11. The papers are 1hr 45mins long. In your exam you get a copy of the periodic table, which is referred to as the data sheet.
The specification which lists all the course content that you need to know can be found here.
Year 11:
Chemistry TRIPLE (H/F) paper 1 19th May (am) 1hr 45mins
Chemistry TRIPLE (H/F) paper 2 13th June (am) 1hr 45mins