4 Replies Latest reply on Oct 27, 2011 8:34 AM by Andres Tretiakov

    Chemistry and Halloween

    Mark Obrien

      Dry ice, latex and corn syrup. What do these three things have in common? Halloween and chemistry, of course. Get into the spirit of the holiday by sharing your favorite Halloween themed chemistry demos, or pick a Halloween related item (think fake blood) and tell us all the ghoulish details about the chemistry that makes for a scary good time.  

        • Re: Chemistry and Halloween
          Mark Obrien

          Here's a fun demo to kick things off:

           

          • Re: Chemistry and Halloween
            Andres Tretiakov

            There are plenty of cool things for a Chemistry Halloween Special!!

             

            U.V. lights + tonic water, petroleum jelly, phosphorescent paints...

             

            What about using a dilute solution of potassium or ammonium thiocyanate and a couple of grams of ferric chloride. First rub some ferric chloide on the arm and then dip a plastic or butter knife in the dilute solution. Slowly apply the knife on the rubbed area of the arm.  A red color is produced by the reaction between the ferric ion and the thiocyanate ion.

             

             

             

            There is also the green flames (boric acid ester) burning inside a carved a jack-o-lantern using boric acid and methanol or ethanol.

             

            The exploding pre-cut pumpking: using water and a couple of pea size pieces of calcium carbide.

             

            http://www.youtube.com/watch?v=ic34g8br2NE&feature=related

             

             

            CaC2 + 2 H2O → C2H2 + Ca(OH)2

             

            This reaction is extremely dangerous so be careful and always use very small quantities.

            Alternatively, you could try CO2 using a bag filled with dry ice, wait until it sublimes and the bag expands or explodes.

             

            Enjoy a safe Halloween,

             

            Andres

            • Re: Chemistry and Halloween
              Monica Hoyt

              I work for a drinking water plant and every year we do Halloween Science in our Conservation Gardens.  We do a variation of Elephants Toothpaste (decomposition of hydrogen peroxide).  But we call it Pukin' Pumpkins.  It gets bigger each year.  This year we are doing 4 shows!

               

              I am always looking for new demos so please reply to these posts!

                • Re: Chemistry and Halloween
                  Andres Tretiakov

                  Hi, following my previous post you could try doing glow in the dark slime simply by making a 4% PVA solution and adding a small amount of activated zinc sulfide (the glowing powder). You then need to mix it thoroughly and slowly add saturated borax solution until you get the slimy consistency your require. This is a great cross-linking polymerisation reaction. Also, the glowing worms work in a similar way, but instead of PVA you need sodium alginate (from algae) and 1% calcium chloride solution. Remember to leave the slime or worm alginate solution in the sun or under U.V. light to ''charge'' the glowing powder so it then glows in the dark.

                   

                  Hope this helps,

                   

                  Andres