Task 2  Chemical Calculations
This task builds on and extends the chemical calculations that you will have encountered at GCSE.
This task has been designed to take you 2.5 hours to complete.
This task has been designed to take you 2.5 hours to complete.
1. Watch this video to remind you how to complete a % by mass question: http://mygcsescience.com/revision/additional/howtocalculatepercentagebymass (7 minutes)
2. Download and complete the "% by mass" worked example task (right  23 minutes) then check your answers on the model answers page. 3. Refresh your memory of other calculation questions by trying some of the questions from this website: http://www.gcsescience.com/m31.htm (90 minutes) Note: You do not have to complete all of these questions! Read through the list quickly then select some to try. If you cannot decide, we suggest you complete 1, 3, 5, 7, 17, 20, 21, 24, 33, 38, 40, 45, 46, 60 and 63. You can check your answers by clicking the Answer link next to each question. 4. Write a blog post, explaining how to calculate one of the following:
Advice: Pick the one you find most challenging so you can learn more from this task! When GCSE Chemistry students are required to complete calculations, the most common error highlighted in examiners reports is an inability to produce a ratio. If you need help doing this, then click here. When you have completed part 4 of the task, you should check how your answer compares with the model answer. End your blog post with a comment about any differences you could see between your answer and the model answer. You may also like to look at the other model answers for the explanations of the other calculations. Perhaps you learned something from doing this? If so, comment about what you have learned, on your blog post. 
Files to download
