Halloween is Spooky (and kind of gross...)

Science is kind of gross sometimes, and that can be part of the process and part of the fun!  To celebrate the last week of spooky season, here's a roundup of some icky Halloween science that you can do at home.

Puking Pumpkin
Materials:
Carved Jack-o-Lantern
Baking Soda
Vinegar
Food Coloring
Large plastic jug or bucket
An outdoor space that can get messy

Directions:
1. Take your pumpkin outside and put it somewhere that's easy to hose off.
2. Take the top off of your pumpkin and add 1/2 cup of baking soda.  Pour slowly so the baking soda doesn't all fall out of the Jack-o-Lantern's mouth.
3. In the jug, mix 2 cups of vinegar with a few drops of food coloring.  
4. Slowly pour the vinegar over the baking soda and watch the chemical reaction erupt right out of the pumpkin's mouth!

The chemical reaction happening inside the pumpkin's mouth is
CH3COOH (l) + NaHCO3 (s) = CH3COONa (l) + CO2 (g) +H20 (l)
Vinegar has the chemical formula CH3COOH. Baking soda is a base also known as Sodium Bicarbonate and has the chemical formula NaHCO3. During this reaction the products are sodium acetate (NaC2H3O2), water (H2O), and carbon dioxide (CO2). Carbon dioxide is the gas that causes the bubbling during the reaction.


Mummified Apples
Materials:
Apples
Recycled containers that can hold an apple and some salt
Large container of table salt, sea salt, Kosher salt, or rock salt
Baking soda
Epsom salts (optional)
Pumpkin carving tool (optional)
Kitchen scale (optional)

Directions:
1. Carve faces into your apples.
2. Create holes all over the apple so moisture can escape.  Core the apple to speed drying (optional).
3. If you have a kitchen scale, weigh the apples and record their weights to keep track of how much water they lose.
4. Fill a container with enough salt to cover the apple.  Label it with the date, the apple’s starting weight and write “salt” or “NaCl” on the container. Put one of the apples in the container and cover it completely, packing salt into all of the holes. Close the container.
5. Fill another container with equal parts table salt and baking soda (and Epsom salt, if you have it).  Mix well, label the container, and cover the other apple with the mixture.  Close the container.
6. After a few days, remove the apples, scrape out the salt and weigh them. Record their weight and return them to the salt. Check them every few days and continue to dry them in salt until they are shriveled up. Replace the salt with dry salt if needed.

In Ancient Egypt, natron was used to preserve mummies.  Natron is a natural salt mixture containing the chemicals sodium carbonate, decahydrate (soda ash), sodium bicarbonate (baking soda), sodium chloride (table salt), and another salt called sodium sulfate.  These salts act as desiccants, which are chemicals that remove water from things.

Fake Blood (but make it science)
Materials:
Three small cups or glasses
Flour
Water
Corn syrup
Chocolate syrup
Red and blue liquid food coloring
Cutting board or plate, preferably white or light in color
Three small spoons
Sink or bowl with water to rinse cups and cutting board
​Towel

Directions:
1. Mix one tablespoon of flour in two tablespoons of water in one cup.
2. Measure three tablespoons of corn syrup into a second cup.
3. Measure three tablespoons of water into a third cup.
4. Add two drops of red food coloring to each cup, and watch how the food coloring disperses over the fluids.
5. Use small spoons to mix the red food coloring with the other ingredients in all three cups.
6. Use the small spoons to take approximately one-quarter teaspoon of red liquid from each cup and place the liquids as separate blobs in a row near the edge of a cutting board or plate. Lift the side with the blobs so the board is tilted and watch how the liquids run down.
7. Water runs way too fast to mimic blood well. Discard the contents of this cup. Rinse off the cutting board and wipe it dry.
8. Pour half of the contents from each of your other two cups into the now empty third cup.
9. Perform your test again, placing small amounts of the three liquids on top of the cutting board or plate, tilting the board and watching how the liquids run down.
10. Continue with the recipe that mimics blood the best, OR, if you did not find a reasonable match yet, proceed with using the third cup with the flour, corn syrup, water and food coloring. 
11. Human blood is always red. To get a realistic look, add a tiny bit of blue food coloring and/or a little chocolate syrup. (Blue food coloring is very strong. It is best to make a drop of blue food coloring on your cutting board or plate, dip the tip of your mixing spoon in it, and use this spoon to stir the tiny amount of liquid in your cup.) Add gradually.  A tiny bit of blue or brown will mimic the bright, oxygen-rich blood. Add a little more for the darker blood that is low in oxygen.
12. Place a blob on the top of your cutting board or plate, tilt the board, and watch it flow.  Add corn syrup, flour, water, food coloring (red or blue) or chocolate syrup, one at a time, to improve your fake blood. Check the results after each addition, and do not forget to keep track of what you added. You will need your final recipe to recreate your fake blood at any time.
13. As a last test, try your blood on your skin, teeth, a surface, or wherever you'd like to use it.