Nitrogen Ice Cream (and some other exciting stuff)

When have you ever gotten to say you were given ice cream in class? Better yet, when has your teacher actually made you ice cream out of nitrogen?

For those of us in 7th period Chemistry, we were able to experience both of the above.

But before we could get to our dessert making, we learned a lesson or two in chemistry.

We started off by having Bailey and Liebs switch identities. Liebs fell asleep on a fur-lined jacket, while Bailey taught the class how to do the pre lab.

Since you probably weren't paying attention to Bailey, I will review what she said.

For number 1, you need to find the partial pressure. So you do 746 mmHg (the total barometric pressure) and subtract 19.8 mmHg (the pressure of the water) to get 726.2 mmHg.

For number two, you use the answer from 1 and use the combined gas law to find V2.

For number 3, you take the .028 g of Mg given in the problem, and use stoich to convert it to moles of H2.

For number 4, you take the volume of the H2 and divide it by the moles you go in question 3. This is the molar volume of the hydrogen at STP.

Remember, the pre-lab is due Monday, so finish it up over the weekend if you haven't already.

Additionally in class, we talked about some new equations/forms of equations.

Since we know that g/mm is equivalent to number of moles, we can use substitution to get the following equation

PV=gRT/mm

Rearranging this equation, we can solve for density, since g/v=density

Pmm/RT=Density (g/v)

Additionally, we can solve for molar mass.

mm=DRT/P ("mm dirty pee")

Now we have 3 ways to get to moles.

1. Pure substances-using molar mass
2. Gases-using PV=nRT
3. STP- 22.4 L/mole

We worked out two problems from the Gas stoichiometry packet.

Here is the work, in case you missed it.

However, while all the above stuff is quite exciting, the most exciting part was when Liebs made us ice cream out of a few simple ingredients: hershey's syrup, milk/cream/half and half, sugar, and liquid nitrogen.

While we may've thought that this concoction was another one of Liebs' silly tricks, it is actually a recipe.

At first it looked like slimy goop, but as soon as the nitrogen worked its magic, we were all mesmerized by the result. We, in turn, were all given a generous portion of homemade chocolate ice cream, and it was quite tasty.

check out the video in the next post, i highly recommend watching it.

Homework: Webassign, pre-lab, worksheets.

The next scribe will be.........Conor.