Liquefying Oxygen

Got some liquid nitrogen, hydrogen peroxide, and a catalyst?

If so, you can collect a test tube’s worth:

To prepare liquid oxygen:

1. Get a standard 3% hydrogen peroxide bottle from the store.
2. I have found that bottles are filled close to the top. Pour off about 50 mL or so. Otherwise the liquid will bubble up into the balloon.
3. Add a pinch of MnO₂ or other suitable catalyst.
   • Adding more catalyst causes too much bubbling and material gets up into the balloon.
   • Chicken liver should work other than there might be big bubbles with material in the balloon.
4. Fit a balloon over the mouth of bottle.
   • It takes a half hour or so to fill the balloon.
   • I found it works best to prepare one filled balloon in advance.
   • Show how to start the reaction and start to fill the balloon.
   • Place that aside for the next class/demo.
5. When removing the balloon, it works well if a pinch clamp is used.
6. Fit the filled balloon over the mouth of a test tube of suitable diameter for the balloon size.
7. Release the pinch clamp.
8. Place in liquid nitrogen.
9. In about ten minutes, there will be a sizable volume of beautiful, ever-so-light-blue, paramagnetic  liquid oxygen.

Can a wet paper towel burn?

1. Roll up a paper towel so that it will fit inside the test tube containing any leftover liquid O₂.
2. Insert the rolled up towel into test tube.
3. Pull out and ignite.
4. It burns ashless!

Enjoy,
Jeff