Energy changes and fuels

The experiments in this section can be used to illustrate, for example, what makes useful fuel and how to measure the energy given out by different fuels. Also included are a range of experiments looking at different examples of exothermic and endothermic reactions.

While we are still at an early stage with this website it's probably more useful to look at the page with our complete list of experiments in alphabetical order. See the list on About this website.

We are starting with GCSE-level experiments.

Experiments

• The reaction between zinc and copper oxide

  An experiment to illustrate the difference in reactivity between zinc and copper and hence the idea of competition reactions.

• Controlled explosion of a methane-air mixture

  Methane and air are allowed to mix and burn in a controlled way until an explosive mixture is reached.

• Bubbles that float and sink

  Carbon dioxide is used to blow bubbles which sink in air. Hydrogen or methane is used to blow bubbles which float in air. Bubbles which sink and then float can also be made.

• Controlled explosion of a hydrogen-air mixture

  Hydrogen and air are allowed to mix and burn in a controlled way until an explosive mixture is reached.

• Combustion of hydrogen in air

  Mixtures of hydrogen and air are ignited, to find which proportions of the two gases by volume produce the loudest explosion (‘pop’).

• A hydrogen powered rocket

  Explosive mixtures of hydrogen and air are used to propel ‘rockets’ made of plastic bottles.

• The thermal decomposition of nitrates – ‘writing with fire’

  The thermal decomposition of sodium nitrate is used to reveal a hidden message written on paper.

• Supercooling - the energetics of freezing

  This experiment demonstrates the phenomenon of supercooling and illustrates the various associated energy changes which occur.

• Endothermic solid-solid reactions

  This experiment demonstrates an unusual endothermic reaction between two solids that occurs without the need for a solvent.

• Energy in or out: classifying reactions

  A simple introduction to show that most reactions involve energy changes and are classified as being exothermic or endothermic.

• The photochemical reactions of chlorine with hydrogen and methane

  The photochemical reaction of chlorine with hydrogen or methane is demonstrated under safe conditions.

• The ‘Whoosh’ Bottle Demonstration

  An alcohol/air mixture is ignited, resulting in a rapid *combustion* reaction, often accompanied by a dramatic ‘whoosh’ sound,

• The alcohol ‘gun’

  A demonstration of the large energy changes that occur during the combustion of alcohols.

• Fat-pan fire!

  A fat-pan fire is used to demonstrate the conditions required to start combustion.

• Energy values of food

  An experiment to estimate the energy present per unit mass of food.

• The cornflour ‘bomb’

  A small explosion, caused by the rapid combustion of cornflour, blows the lid off a tin.

• Exploding bubbles of hydrogen and oxygen

  Bubbles containing a mixture of hydrogen and oxygen gas, produced by electrolysis, are ignited and explode.

• The fractional distillation of crude oil

  This experiment simulates the industrial fractional distillation of crude oil in the laboratory.

• Cracking hydrocarbons

  A mixture of alkanes is cracked by passing the vapour over a heated catalyst. Tests for unsaturation are used to show the presence of alkenes in the products.

• Heat energy from alcohols

  In this experiment students burn various alcohols and compare the heat energy produced.

• Exothermic metal-acid reactions

  Measuring the rise in temperature in the exothermic reactions of metal powders with dilute acids.

• Exothermic or endothermic?

  Students look at the temperature changes in four reactions to see if they are exothermic or endothermic.

• Sodium ethanoate ‘stalagmite’

  A demonstration showing rapid crystallisation of a supersaturated solution

• Chemiluminescence – cold light

  Oxidation of luminol by sodium chlorate(I) produces a blue chemiluminescent glow.

• Ammonium dichromate volcano

  An eruption of green ash, sparks and steam occurs as ammonium dichromate(VI) decomposes exothermically.

• Spontaneous exothermic reaction

  The delayed reaction between potassium manganate(VII) and glycerol.

• Exploding balloons

  Demonstration experiment involving exploding balloons containing mixtures of hydrogen and oxygen in varying proportions.

• Identifying the products of combustion

  A simple demonstration to identify the gaseous products of the combustion of hydrocarbons.

• Measuring heat energy of fuels

  Measuring the heat energy produced by the combustion of alcohols