Superbugs and their chemical reactions

This resource accompanies the Education in Chemistry article Wonder weapons where you can read about even more bugs with chemical superpowers.

Learning objectives

1. Draw an energy level diagram for both a catalysed and uncatalysed reaction.
2. Explain the effect of catalysts on the profile of a reaction.

Introduction

Energy changes in reactions can be described as exothermic and endothermic. Endothermic reactions absorb energy from the surroundings and exothermic reactions release energy to the surroundings.

There are lots of examples of animals across nature which rely on chemicals or a mixture of chemicals to help them avoid being eaten. Some spray acid whereas some spray oils. However, the bombardier beetle is slightly different. In this activity learners will read an excerpt from the article Wonder weapons published in Education in Chemistry and then use their knowledge to answer questions on exothermic reactions, the effect of catalysts and balancing equations.

Differentiation

There are two differentiated versions of the student worksheet. In the unscaffolded version, learners are expected to be able to draw a sketch graph including their own axes. In the scaffolded version, the axes are already drawn, as are the start and end points. Learners will add labels to the axes and complete the reaction profiles. Further scaffolding includes fill-in-the-gap answers, while the unscaffolded worksheet requires learners to write their own sentences.

Answers covering both worksheets are provided in the teacher notes.