How do you colour a jelly baby?

UNDERSTANDING YOUR FOOD<br /> the ultimate educational resource<br /> TEACHER NOTES<br /> <br /> teachers’ notes C2.1<br /> KS3<br /> science or technology<br /> Timing - 40 - 60 minutes<br /> As there are waiting times in this<br /> experiment, it is advisable to have<br /> other activities available to occupy<br /> pupils.<br /> Pupil activity sheet C2 accompanies<br /> this activity.<br /> Requirements<br /> • 2 diced jelly babies, of the<br /> same colour (see footnote)<br /> • 50 cm<br /> 3or 100 cm<br /> 3beakers<br /> • stirring rods<br /> • distilled water<br /> • small measuring cylinders<br /> • 2M hydrochloric acid<br /> • teat pipettes<br /> • watch glasses of a suitable size<br /> to act as a lid for the beakers<br /> • 50 cm lengths of100% wool,<br /> white or undyed<br /> • hot plates for heating (if not<br /> enough of these are available, a<br /> water<br /> bath can be used; technology<br /> teachers may also be able to use<br /> a hob)<br /> • card, sellotape, glue, etc. for<br /> making a display of the results<br /> • safety goggles<br /> More able/older groups can go on to<br /> the next investigation which<br /> analyses the colours using<br /> chromatography.<br /> C2. How do you colour a jelly baby?<br /> Pupils investigate the colours used in jelly babies by extracting the<br /> colour and using it to colour lengths of wool.<br /> SAFETY NOTE: CARE IS NEEDED WHEN USING ACID AND<br /> HOT EQUIPMENT.<br /> The volumes used are not critical. If you intend the pupils to also<br /> carry out investigation C3, it is advisable to use twice the quantity of<br /> wool in this investigation, that is, 2 x 50 cm lengths for each colour<br /> of jelly baby.Answers to questions on Pupil activity sheet C2:<br /> 1. A coloured solution is produced.<br /> 2. The wool takes up (adsorbs) the colour from the solution. It is<br /> interesting to note what colours are left behind in the beaker. (For<br /> example, black jelly babies from Tesco make the wool turn a<br /> red/brown colour but leave a green colour in the beaker.)<br /> 3. The wool and sweets make a very colourful display which seems a<br /> suitable way of recording the results.<br /> Their are a number of discussion points such as:<br /> • why are colours necessary in this product?<br /> • which manufacturers use the least number of colours?<br /> • how do you get 6 different colours of jelly babies from only 3 added<br /> colours?<br /> • why do different manufacturers use different colours?<br /> • why do some manufacturers use natural rather than artificial colours?<br /> • can you tell the flavour and colour of a jelly baby without seeing it?<br /> As there are waiting times in this experiment, it is advisable to have other<br /> activities available to occupy pupils.<br /> Jelly babies: different brands do contain different colours; pupils may like<br /> to investigate these differences and discuss why some manufacturers use a<br /> minimum of 3 colours (and yet the packet contains 6 different colours)<br /> while other manufacturers use many more colours. It is also interesting to<br /> find out which manufacturers use natural rather than artificial colours.<br /> <br /> HOW DO YOU COLOUR A JELLY BABY? pupil activity C2<br /> The manufacturers of jelly babies add colours to these sweets. Different<br /> manufacturers add different colours. Can you tell the flavour and colour of a jelly<br /> baby if youdon’t look atit before you eat it? Try this out!<br /> In this investigation you are going to remove the colours from jelly babies and transfer<br /> the colours to long pieces of wool.<br /> Read the safety note before you begin.<br /> SAFETY NOTE<br /> DO NOT EAT OR TASTE ANY OF THE SUBSTANCES<br /> USED IN THE INVESTIGATION.<br /> BEWARE! YOU WILL BE USING HOT WATER!<br /> YOU WILL BE USING DILUTE ACID. WASH OFF ANY SPLASHES WITH<br /> PLENTY OF WATER. TELL YOUR TEACHER WHAT HAS HAPPENED.<br /> REMEMBER TO WEAR GOGGLES<br /> Method<br /> 1.Place tworedjelly babies in a small beaker. Add 10 cm<br /> 3<br /> of distilled water.<br /> 2.Heat this and stir with a stirring rod until the jelly babies dissolve. This should only<br /> take a couple of minutes.<br /> 3.Add 1 cm<br /> 3<br /> of dilute acid to the beaker and stir.<br /> 4.Add one length (about 50 cm) of pure white wool to the beaker. Cover the<br /> beaker with a watch glass.<br /> 5.Carry on heating the mixture for about three minutes.<br /> 6.Using your stirring rod, remove the wool and place it in an empty beaker.<br /> Wash the wool thoroughly using plenty of distilled water. Allow the wool to dry.<br /> 7.Repeat this method with the jelly babies of the other colours.<br /> Questions<br /> 1.What happened to the water when you dissolved the jelly babies?<br /> 2.What happened to the wool when you put it in the jelly baby solution?<br /> 3.Make a display of your results.