University of Northern Iowa chemistry students are use putting a new twist on Halloween spook houses. The goal of traditional Halloween haunted houses has been one thing — to scare the heck out of you. But UNI students in the American Chemical Society have put the science they’ve learned into a Halloween house that features flash freezing with liquid nitrogen and a simulated grain-bin explosion.

Senior Megan Kelly of Ankeny says they provide the thrills, but also invite the local elementary and junior high kids who visit the house to participate. Kelly says the point of it is to work with kids in science and get them thinking about why some things work and why some don’t. She says they hope to get the kids asking ‘How does that work?’ and then they can explain the chemistry and science about it.

Kelly says the simulated grain bin explosion is a good example. They take the powder of a ground up plant called lydopodim, and show how a grain bin explosion happens. Kelly says it’s a really fine powder that won’t blow up until you blow it around in the air and give it enough surface area to catch on fire and provides "quite a big fiery explosion." But if the powder is just sitting on the table, it won’t do anything.

Kelly says the Halloween house gives the kids a learning experience and in a safe setting. She says it’s a major concern that everything is safe for the kids, as it is in a controlled setting. Kelly says putting the project has also helped them learn. Kelly says they’ve learned there are some things you have to work through, as some demos don’t work the first time, and you have to keep doing them even though they can be frustrating. She says they eventually learn the best way to get the demos to work.

The schoolkids are scheduled to tour the house in the university’s science hall Wednesday night. The Halloween house is part of the National Chemistry Week activities for the UNI students.

Audio: Dar Danielson reports. :50 MP3