Can Baking Soda Substitute for Baking Powder in a Recipe?

Ideas to try out came from this website http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p008.shtml

To do this experiment you will need the following materials and equipment:

• Muffin pans
• Optional: paper muffin cups (for lining pan)
• Mixing bowl
• Measuring cups and spoons
• Muffin ingredients (enough for 4 half-batches, see recipe in Experimental Procedure below for more details):
  • Flour
  • Corn meal
  • Eggs
  • Sugar
  • Butter
  • Baking powder (to make "normal" muffins, for comparison)
  • Baking soda
  • Cream of tartar (potassium bitartrate)
• Oven
• Oven mitts
• Cooling rack
• Timer

1. Do your background research so that you are familiar with the terms, concepts, and questions, above.
2. Use the muffin recipe below as a starting point (Beard, 1972), or pick your favorite muffin recipe and make a "half batch" of 6-8 muffins. Note: The recipe shown below will make 6-8 muffins. You can "halve" your own recipe by dividing the required amount of each ingredient by two. Be sure and note the ingredient amounts you use!
   1. 1/2 cup all-purpose flour
   2. 1/2 cup cornmeal
   3. 1/2 to 1 tablespoon sugar (to your taste)
   4. 2 teaspoons baking powder or
   5. cream of tartar and baking soda (see below for amounts to use)
   6. 1 egg, slightly beaten
   7. 1/2 cup milk
   8. 1/8 cup melted butter
   9. Mix all of the dry ingredients together in the mixing bowl. Make a well in the center and the beaten eggs, the milk, and the melted butter. Stir to a smooth batter. Fill well-buttered (or paper-lined) muffin pans about two-thirds full. Bake at 425°F for 15–20 minutes, or until nicely browned and baked through.
   10. Tip: do your best to start each muffin off with the same amount of batter. You can use a teaspoon to move small amounts of batter between the different cups in a pan to get the muffins equalized. On the other hand, you don't want spend too much time on this, because the baking powder starts working as soon as it touches liquid.
3. Remember to use oven mitts when putting the pans in the oven and when taking them out again.
4. Place the muffin pan on a cooling rack for a few minutes, and then tip the muffins out. Let them cool for a few more minutes before handling (or sampling!) them.
5. Make one half-batch following the baking powder recipe (or your own halved recipe) above, and then four additional half batches, substituting the following amounts of cream of tartar and baking soda:
   1. 0 teaspoons cream of tartar, 3/4 teaspoons baking soda,
   2. 1 teaspoon cream of tartar, 1/2 teaspoon baking soda,
   3. 1 1/2 teaspoons cream of tartar, 3/4 teaspoons baking soda,
   4. 2 teaspoons cream of tartar, 1 teaspoon baking soda.
6. Remember to keep track of which batch is which!
7. Compare the four different half-batches of muffins:
1. Measure the height of each muffin in each batch and compute the average height for each batch. Note: if one muffin is much smaller than all the others, don't include it when calculating the average height.