Atom economy, percentage yield and green chemistry misconception buster

No comments

Probe your learners’ understanding of the calculations and the meaning behind them

This resource is designed to identify and target misconceptions at the three main pinch points: calculating percentage yields, calculating atom economies and evaluating sustainability in industrial processes and green chemistry. It accompanies Teaching atom economy, percentage yield and green chemistry post-16 in Education in Chemistry, where you will find more ideas, activities and tips for teaching this topic and avoiding misconceptions.

Download this
A student worksheet offering multiple choice questions and differentiated follow-up tasks, plus teacher notes with answers and explanations. Pdf and editable versions.
Download All

Learning objectives

By the end of this resource, students will be able to:

Write equations for percentage yield and percentage atom economy calculations.
Calculate percentage yield and percentage atom economy given experimental data and chemical equations for processes.
Interpret and evaluate percentage yields and percentage atom economies for industrial processes.
Suggest how to improve percentage yields and percentage atom economies for industrial processes.
Evaluate industrial sustainability given appropriate information.

How to use the resource

Activity 1 consists of 18 multiple choice questions. Instruct learners to read each question carefully – using the data provided – and tick an answer. There is one correct answer per question. The answer to each question includes an explanation for you to share with learners.

After learners have marked the multiple choice questions either by peer- or self-assessing, ask them to complete the relevant follow-up tasks to target areas for improvement and increase their understanding of certain topics.

If appropriate, guide learners to follow-up tasks based on misconceptions you have already identified throughout the course or for further practice if they get 18/18 on the quiz. Activity 2 is fully differentiated for learners to target their own misconceptions identified from the multiple choice quiz.

You can choose to use task c separately as it requires students to access research resources.

More resources

A misconception buster on the topic of electrochemical cells is also available .
Encourage students to explore sustainable development through calculations with this green chemistry worksheet.
Carry out the preparation of 2-hydroxybenzoic acid (or use the aspirin screen experiment). Then get students to discuss their percentage yields and where losses have occurred.
Show how Florence, chief technology officer and co-founder of Lixea, turns waste wood into renewable raw materials and fuel to help reduce the world’s reliance on petroleum.

Extension opportunities

These concepts apply to many industrial processes. One example is in the production of (+)-limonene from orange peel (overview available from FutureLearn). As a follow-up activity, get students to read about the process and evaluate whether the new method is more sustainable than conventional methods. The 12 principles of green chemistry will guide their thinking.

Encourage students to research further applications of decision-making for industrial processes, if appropriate.

Answers

Answers to all multiple-choice questions in activity 1 are provided in the teacher notes along with explanations you can share. A recommended follow-up task is attached to each question. Full answers for each follow up task in activity 2 are also provided, plus suggested ideas for the extension task.