Avogadro’s Lab

Education in Chemistry is a magazine produced by the Royal Society of Chemistry to promote chemistry teaching and inform chemistry teachers. Avogadro’s lab was part of a regular insert, aimed at schools, known as The Mole. Experiments in Avogadro’s lab can be carried out at home or in school and are often a slightly more detailed version of some experiments outlined in these web pages.

From 2016, however, The Mole will be undergoing an overhaul. We look forward to what new opportunities the future will bring.

Dyes and mordants – November 2015

This issue deals with colouring cloth. A dye is soluble and will tend to be washed out of cloth as it is repeatedly washed. A mordant helps lock the dye molecules to the fibres of the cloth. Some dyes, however, don’t need a mordant, which is why tea stains can be sol difficult to remove. Turn to the flip book page or download The Mole as a pdf.

The speed of light – September 2015

Over the years there have been many attempts to measure how quickly light travels. In this issue we find out how it is possible to get a measurement of the speed of light in your own kitchen. All you will need is a microwave, and some chocolate, or marshmallows, or old till receipts or a poppadom. Turn to the flip book page or download The Mole as a pdf.

Gels and their uses – July 2015

The 2015 Global Experiment of the Royal Society of Chemistry deals with the absorbent properties of hydrogels. This month’s article looks at a number of other uses to which we put gels, from gathering stardust to making the tallest jelly. Turn to the flip book page or download The Mole as a pdf.

The Chemical History of a Candle – May 2015

The International Year of Light and light based technologies continues with a reprise a look back to the time when all light production was chemical. It also takes the opportunity to reprise Michael Faraday’s famous lecture series: the chemical history of a candle. These lectures were one of the original “Christmas Lecture” series. They are all detailed in a book with the same name and a new edition contains facsimiles of Faraday’s own notes. Turn to the flip book page or download The Mole as a pdf.

Mechanical Light – March 2015

Another contribution to the International Year of Light with a brief look at light created mechanically. Peeling sticky tape from a roll or crushing sugar both produce light. The light is, however, very dim, and one needs to be in a dark environment with eyes accustomed to the gloom to be able to detect it. Turn to the flip book page or download The Mole as a pdf.

Crystals in the sky  – January 2015

2015 has been designated the International Year of Light. This article tries to bridge between the International Year of Crystallography and the International Year of Light by considering the optical effects that ice crystals create in the sky. The article is not long enough to go into much detail and focusses on one phenomenon, that of perhelia (false suns or sun dogs). Details can be found in the flip book or by downloading the whole magazine as a pdf.

Fractional crystallisation  – November 2014

Crystals can be purified from mixtures by using the different degrees of solubility. This issue describes a simple experiment which exploits this effect. The results can be analysed using taste – one of the few examples where this is permissible. Details can be found in the flip book or by downloading the whole magazine as a pdf.

Handedness of molecules  – September 2014

Continuing with crystals this issue explores the handedness of sugar. Handedness in chemistry is known as chirality and is extremely important in biology and therefore when making molecules to act as drugs. Details can be found in the flip book or by downloading the whole magazine as a pdf.

Edible Crystals – July 2014

The column this issue considers how to represent crystals. Using only marshmallows and cocktail sticks large three dimensional models of crystals can be built. The biggest advantage, of course, is that you can eat the marshmallows when you have finished (or even while you are building)! Details can be found in the flip book or by downloading the whole magazine as a pdf.

Catalytic metals – May 2014

This issue continues the theme of catalysis. This time we concentrate on inorganic catalysts, such as those found in catalytic converters. Details can be found in the flip book or by downloading the whole magazine as a pdf.

Speedy reactions – March 2014

Catalysis is the topic of this issue. We look at what a catalyst does and use the enzymes in yeast to break down some hydrogen peroxide. Details can be found in the flip book or by downloading the whole magazine as a pdf.

A simple cell – January 2014

In this issue we build a simple electrochemical cell. There are instructions to do this with two dissimilar metals and an acid, such as vinegar. One of the metals dissolving usually makes hydrogen gas. If we make the electrons involved flow through a circuit first we can make electrical power and hydrogen. Details can be found in the flip book or by downloading the whole magazine as a pdf.

A little light relief – November 2013

In this issue we build a spectroscope. There are instructions and the link to the template. Essentially one makes a box with a couple of holes in which contains a DVD. The DVD acts as a diffraction grating to split light up into the component colours. Details can be found in the flip book or by downloading the whole magazine as a pdf. Alternatively you may just want the template. To use the template on its own fold along the solid lines and cut the dotted ones. The DVD slips into the slit, but do not worry that it sticks out a bit – it is meant to do that.

The Global experiment – September 2013

For Chemistry Week 2013 (16-23 November) the Royal Society of Chemistry has organised a global experiment. It is based on the vitamin C practical below. The idea being that groups can test fruit and vegetables for vitamin C content and log the results on the central website. The article is available for download here. The website with further details can be found here.

Vitamin C – July 2013

The experiment described in this issue of Avogadro’s lab uses tincture of iodine to measure the amount of vitamin C in a sample. Starch is used to indicate the presence of iodine and the key is the fact that vitamin C is able to reduce iodine to iodide. If iodine is added to a vitamin C and starch mixture the dark colour of the iodine starch complex is formed when all the vitamin C is used up. Alternatively a vitamin C containing solution may be added to an iodine/starch mixture. The endpoint in the latter is when the iodine has been used up and the colour is lost. (The former is actually the easier technique to use.) The article may be found here.

Bubbles – May 2013

Moley met a friend in a coffee shop this time, and they ended up discussing foams. The experiment that is described is one to test the relative stability of foams. The suggestion made here is to compare the stability of a foam produced from egg white to that of one produced with detergent. The article can be accessed here.

Water into wine – January 2013

In this issue Moley was busy replicating a “water into wine” experiment. In this case it is actually red wine into white wine, but the idea is the same. Fortunately it uses washing soda, vinegar and turmeric for the effect so everything is readily available in the kitchen. The article is available for download here.

Tags: Education in Chemistry, Avogadro’s lab, The Mole, Crystals, Chirality, Handedness, Spectroscope, Marshmallows, Global Experiment, Water into Wine, Foam, Bubbles, Vitamin C, Dyes, Light, Catalyst, Crystallisation, Fractional, Gels.