Halloween chemistry for all the family

If you look, you can find a way of bringing some chemistry fun and mayhem into all the big annual holidays!  Whilst the idea of celebrating Halloween has been seen as more of an American pastime than a typically British one it seems that us Brit’s are definitely getting on-board!

Our local shops are full of pumpkins and there’s definitely an abundance of sweets for anyone preparing for trick-or-treat guests on the big night.  For those who don’t celebrate this deliberately unusual event we expect our neighbourhood children (accompanied by a responsible adult!) to dress up in spooky outfits and knock on our door, hoping for gifts of edible goodies! Although the general idea of the event is for the children to somehow trick or punish the owner of the house if they don’t give them treats you’re more likely to just see a sad face than an actual trick!

According to www.history.com “…Halloween is thought to have originated with the ancient Celtic festival of Samhain, when people would light bonfires and wear costumes to ward off roaming ghosts. In the eighth century, Pope Gregory III designated November 1 as a time to honor all saints and martyrs; the holiday, All Saints’ Day, incorporated some of the traditions of Samhain. The evening before was known as All Hallows’ Eve and later Halloween.”

So how can we get some chemistry in on this fun-filled night? There are loads of ideas online, most of which seem to feature chemicals we don’t think you can find in your local supermarket or lots of dry ice. We’ve hunted around for things you can realistically do with the family though and these are a couple of the features we found:

Rainbow fire pumpkin (click for the original article)

Although this does involve fire (so obviously must only attempted with a responsible adult) it’s quite straight forward. 

  • Smear hand sanitizer all over the outside and inside of the carved pumpkin.
  • Dust the pumpkin with boric acid or borax. You don’t need very much to achieve a nice colored effect. Just a light sprinkling will suffice – this is available from most hardware shops in the cleaning section.
  • Ignite the jack-o-lantern.
  • The flame goes out on its own fairly quickly as the alcohol in the hand sanitizer gets used up, leaving you with water.

How It Works

Boric acid or borax (either works) emit a green light when heated in a flame. The pumpkin gives off a multicoloured fire because you have the natural blue of the alcohol flame from the hand sanitizer, the green from the boric acid, orange light coming through the carved pumpkin, plus other colors from where the pumpkin juice mixes with the flame.

Make ectoplasm slime! (click for the original article)

You can really go mad with this – adding glow in the dark paint or different colours.  It’s very simple though!  As you’re heating with a microwave please ensure that a responsible adult is supervising at all times.

All you need is 1 teaspoon soluble fiber, 1 cup of water, some food colouring, and the use of a microwave oven.

  • Pour the water and fiber into a large microwave-safe bowl.
  • Microwave the ectoplasm on high power for 3 minutes.
  • Stir the ectoplasm. Return it to the microwave and heat it for another 3 minutes.
  • Stir the ectoplasm and check its consistency. If you want drier ectoplasm, microwave the ectoplasm another minute or two. Continue checking the ectoplasm and microwaving it until you achieve the desired consistency.
  • Add a drop of food coloring and/or some glow paint, if desired. You’ll get an interesting effect if you incompletely mix the coloring into the ectoplasm, such as multicolored ectoplasm or ectoplasm slime with glowing streaks
  • Store the ectoplasm in a sealed baggie to prevent dehydration. The slime will last for a week or longer, as long as you keep it from drying out.

Are you doing anything chemistry-related for Halloween in your lab or with your kids? We’d love to see what you come up with so please tweet us at @Asynt or post a picture at www.facebook.com/asynt – thanks!  In the meantime, we hope you enjoy Dr Ffion Abraham’s “Methylated Spirits” pumpkin!