WJEC Chemistry for A2: Student Bk

5 About this book MATHS An assessment of your mathematical skills is very important, this feature demonstrates some common uses of mathematics in chemistry. You are preparing for a chemistry examination not a maths exam, but it is still important to apply numerical analysis, and these features will help you to do so. Mathematical requirements are given in Appendix C, at the end of the specification course content. The level of understanding is greater at the A2 level and some requirements are equivalent to Level 3 (post GCSE). HOW SCIENCE WORKS In some cases it helps you to see how chemistry itself has evolved, the interaction between theory and experiments as well as their limitations. Science works by using theories and ideas, knowledge and understanding, IT and ICT and experimental investigations to obtain, analyse, interpret and evaluate data. Also by considering the applications of science, benefits, risks and ethical issues it evaluates how society may use science to inform decision making. A2 Chemistry – a summary of assessment Assessment in the A2 specification consists of two written papers of 1 hour 45 minutes each, and there is one paper for each of two units that are themselves 25% of the A level qualification. There are 80 marks available on each paper. In addition, practical work at A2 is assessed through Unit 5. This consists of an experimental task, of up to three hours in duration and a one hour written practical methods and analysis task. Both parts carry 30 marks each and the overall mark counts 10% of the marks towards the overall qualification. Unit 3 deals with Physical and Inorganic Chemistry Unit 4 deals with Organic Chemistry and Analysis Unit 5 deals with the Practical aspects of chemistry Each of the papers in Units 3 and 4 consists of Section A short answer questions (for 10 marks), and Section B structured and extended response answer questions. Section B questions are worth 70 marks. There are no multiple choice questions in these papers. Assessment objectives (AOs) and weightings Assessment objectives Examination questions are written to reflect the assessment objectives described in the specification. You must meet the following assessment objectives in the context of the subject content, which is given in detail in the specification. AO1 Covers showing knowledge and understanding of all aspects of the subject. AO2 Covers applying this knowledge and understanding theoretically, practically and qualitatively and quantitatively. AO3 Covers analysis, interpretation and evaluation of scientific information and evidence, making judgements, reaching conclusions and developing practical design and procedures. The weightings of these objectives – which are the same for Units 3 and 4 – are as follows (for the whole A level qualification): AO1 – 7.2% (or for each paper 28.8%) AO2 – 10.6% (or for each paper 42.4%) AO3 – 7.2% (or for each paper 28.8%) For Unit 5 AO1 – 2.0% (or for this unit 20%) AO2 – 5.0% (or for this unit 50%) AO3 – 3.0% (or for this unit 30%) Mathematical skills These will be tested across all three papers and have a total weighting of at least 20%. The skills include those tested at AS level and some extra skills, which include the use of logarithms. The specification lists these requirements in more detail. Practical work The practical work at A2 level is tested through Unit 5 and details of this are given later in the book.