Deducing an empirical formula experimentally: using moles
I can describe and carry out an experiment to determine the empirical formula of a simple compound.
Deducing an empirical formula experimentally: using moles
I can describe and carry out an experiment to determine the empirical formula of a simple compound.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- Small masses of a substance, including magnesium, can be easily heated in a crucible.
- The crucible needs to be opened periodically to allow air (i.e. oxygen) to enter the apparatus.
- Lifting a crucible lid too often or for too long may lead to loss of product (i.e. lower final mass recorded).
- Using practical data and conservation of mass, chemists can calculate unknown reactant masses.
- Reactant masses can determine the empirical formula of a substance, including the ionic molar ratio of a metal & oxygen.
Keywords
Empirical formula - A substance's empirical formula shows the simplest whole number ratio of atoms of each element in a compound.
Evaluate - To evaluate something is to make a judgement about it with respect to a particular purpose.
Mole - A mole of something is 6.02 × 10²³ of it. The mass of a mole of a substance is its relative mass expressed in grams.
Relative atomic mass - Relative atomic mass is the mean mass of an atom relative to 1/12th the mass of an atom of carbon–12.
Common misconception
Pupils think that simply ensuring a fair test will improve data collecting in a practical.
Evaluating a practical is an often overlooked skill. Challenge pupils to focus on the equipment chosen and/or the method followed to consider how better data might be collected.
To help you plan your year 10 chemistry lesson on: Deducing an empirical formula experimentally: using moles, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 10 chemistry lesson on: Deducing an empirical formula experimentally: using moles, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 chemistry lessons from the Calculations involving masses unit, dive into the full secondary chemistry curriculum, or learn more about lesson planning.
Equipment
balance (ideally 2 d.p.) magnesium strips (~3 cm) crucible and li. Bunsen burner tripod + clay triangle heatproof mat tongs
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
Loading...
