Comments on: Exploding Pumpkins

By: conner roberts

conner roberts — Mon, 31 Oct 2011 19:38:40 +0000

I think your experiments are awesome. what would be best without mager explosions

By: Cari

Cari — Fri, 29 Oct 2010 12:34:32 +0000

I reuse the same pumpkin for all of my classes.

By: David Pribyl

David Pribyl — Fri, 22 Oct 2010 18:03:14 +0000

I have the Shakashiri series, but can’t find that reference.
which volume? Which page / article?

By: Julie Gintzler

Julie Gintzler — Mon, 18 Oct 2010 15:29:59 +0000

Ariana – If you search for “exploding pumpkins” on our website, you’ll find a page that explains the reaction (in very general terms). As you know, we don’t put specific quantities on the website because we don’t want people to get hurt. I have to tell you that this is EXTREMELY dangerous. You should be wearing a full face shield, coat, safety gloves and safety glasses. I would strongly recommend that you do this for the first dozen practice pumpkins you blow up until you really get the hang of it. It is not our intent to be evasive, rather to protect the safety of those who use our site and are not trained in the usage of chemicals. The experiment starts with the carving of a Jack-O’Lantern and the build up of acetylene gas which is ignited. The truth is that there really is no exact recipe since each pumpkin is different and there’s always the chance that too much acetylene gas built up in the pumpkin will make the whole thing will explode! There is a set of chemical reference books called “Shakhasairi Chemical Demonstrations” series. This chemical text series is designed as a high level chemical demonstration text. You will find the full experiment details in these books. Oh… and the pumpkin can be re-uesd as long as you haven’t blown him up.

By: Ariana

Ariana — Sun, 17 Oct 2010 03:41:44 +0000

I am an 8th grade science teacher and would LOVE to do this experiment around Halloween for the students. I have 7 sections and was wondering if you can “reuse” the pumpkins or if you need a new one for each explosion.

Also, can this be done in the classroom or will we need to go outside to do it? I don’t want to set off any fire-alarms (that doesn’t look too good for a first year teacher).

By: Paul

Paul — Sat, 22 Aug 2009 18:20:07 +0000

After you perform the experiment, how do you dispose of the waste?

By: Kathy M

Kathy M — Fri, 31 Oct 2008 04:19:28 +0000

Thanks so much Cari!!!
I have 6 carved pumpkins ready to go for 5 classes. Your description seems to be the best and it makes me feel a bit more relaxed about this demo. The kids oughta love it!! I can’t wait for 1st period!!
More tomorrow after all my classes……… cross your fingers!
8th Grade Science Rules!!!
Happy Halloween to all!!!

By: Cari

Cari — Thu, 30 Oct 2008 23:09:47 +0000

I tried it this morning, ended up starting with a smaller amount of calcium carbide but ended up needing between 2-2.5g. I placed the calcium carbide in a little cup I made out of aluminum foil, added just enough water to cover the calcium carbide (it fizzes at that point as the gas immediately begins to form, put the lid back on the pumpkin, blocked the hole in the back of the pumpkin with my hand, had a pre-lit candle attached to a meter stick in a safe place so that the candle was not in danger of causing a fire, counted to 10 brought the tip of the candle to the hole (me at opposite end of the meter stick), and boom, it worked perfectly. The pumpkin is on fire so to speak for a few seconds but it rapidly went out. The pieces of the pumpkin were perfectly fine afterwards so one pumpkin should work but I’m gutting out two more tonight just to have them. If anything, they become room decorations. I’m very excited to do it tomorrow. My kids will be across the room for that just in case factor but the pieces basically went out two feet from the pumpkin so I’m not too worried…. better to be safe than sorry though. Have fun… Happy Halloween!

By: britny

britny — Thu, 30 Oct 2008 21:11:54 +0000

hi i am a 12th grade student currently taking chemitry, and i am doing this experiment for a grade 9 science class. this is how i am doing, and so far the reactions ive gotten it pretty good, and how my group is doing it it’s pretty safe.. 1st we carved the pumpkin to what we wanted, put the pieces back in, carvd a hole in the back. then we measure 2grams of calcium carbide (our pumpkin was medium sized) and 20ml of water, which then the water reactes with the carbide and makes a huge loud bang. we attached a buring splint (popsicle stick) to a meter stick and then lite the pumpkin that way to prevent any injuris, also we used plastercine to cover the hole we carved in the back to stop the gas forming to seep out the hole… the 1st time we did this without the plastercine and the meter stick with the splint and my friends hand got a tad burned. so we found this way to be very very useful and it prevents alot of injuries if done properly and handles with care.

By: Barbara

Barbara — Thu, 30 Oct 2008 14:04:34 +0000

Cari, please let me know how yours turns out. I have all the calcium carbide and the pumpkin carved, just feeling a little anxious about doing this in front of students and want to practice. Also, not sure if I will need another pumpkin or not.

By: Susan

Susan — Thu, 30 Oct 2008 12:01:42 +0000

Let’s all take Steve’s advise and leave this experiment to teachers and professionals who have the proper ingredients and environments to perform this.

By: Cari

Cari — Thu, 30 Oct 2008 11:31:44 +0000

I am being careful and I’m working with another chemistry teacher who is more experienced but regardless, I bought three pumpkins. I’m trying it today without any kids around to test with the amounts because I’m going for the eyes, nose and mouth pop-out and not pumpkin exploding guts everywhere…

By: rose

rose — Wed, 29 Oct 2008 23:41:17 +0000

Cari,
I’ve got the supplies but haven’t tried it yet myself. I have looked up other people’s experiments on youtube. Some of the people playing with this stuff are working on Darwin Awards. When I do this, I will start small. I don’t want to completely blow up my pumkin on the first try but I would expect to need to have back up pumpkins… since I don’t know what I’m doing… that’s why it’s called research. Please be careful.

By: Cari

Cari — Tue, 28 Oct 2008 21:53:41 +0000

I am a chemistry teacher with access to all materials, but wasn’t sure if I would have to go out and buy multiple pumpkins to get the job done + I wanted to practice on Thursday to get the technique and amounts correct before demonstrating for my students. Can the same pumpkin be used multiple times or must a new one be used each time?

By: Steve Spangler

Steve Spangler — Mon, 27 Oct 2008 19:39:59 +0000

Just a quick reminder that this is not a "do it at home" kind of activity. You should be a science teacher who has been trained in how to do it before you try it out. You can find out information that I posted on the Exploding Pumpkins experiment. Steve

By: Bruce

Bruce — Sat, 25 Oct 2008 09:17:14 +0000

Leah,

One reference above mentioned rubbing alcohol. 91% from your favorite wal store should do the trick. I have used it with great success in potato cannons, so it should do this just fine. Put it in a small spray bottle that gives a good mist so it mixes well with the air. Always try it yourself before the demo and make sure you are not alone. Fire can be a dangerous thing. I singed my bangs and eye lashes burning black widows with this set up.

By: Leah Rackley

Leah Rackley — Thu, 16 Oct 2008 19:53:34 +0000

I would like to do an experiment like this for my children’s church class, but I do not have access to chemicals. Is there a way to perform this experiment with everyday supplies.

By: Steve Spangler

Steve Spangler — Wed, 08 Oct 2008 14:45:51 +0000

Hi Ian,

It’s great to see an 8th grader with so much science ambition! However, this experiment is not one that I would recommend to anyone other than trained professionals. Ask your chemistry teacher if he/she could perform this experiment for Halloween… it’s a great reaction, but much safer when performed by an adult who is trained to work with these dangerous chemicals.

Steve

By: Ian

Ian — Tue, 07 Oct 2008 22:47:00 +0000

Hi I am in the 8th grade and thinking about doing this experiment I was looking at the video pretty sure i have everything but it said your supposed to cut a whole in the back and thats where you light it but wouldn’t that just #1 burn you if you were lighting it from behind? #2 wouldn’t the explosive energy just go out the back? Thank you.

By: Rashmi

Rashmi — Wed, 07 Nov 2007 15:16:34 +0000

I am a chemistry teacher and I want to do this experiment with ISOPROPYL ALCOHOL mixture and PHENOPHTHALEIN.Can You please guide me how much quantity of each is required?