Yes, of course! Otherwise everything would taste half as salty as it was supposed to.
Yes you do
Baking powder in a recipe helps your item rise when baking.
Yes it aids in the rising. When a recipe contains baking powder and baking soda, the baking powder does most of the leavening. The baking soda is added to neutralize the acids in the recipe plus to add tenderness and some leavening.
no
The original Nestlés Toll House cookies (chocolate chip cookies) recipe calls for baking soda, not baking powder. There is no substitute for baking soda or baking powder in a recipe. You have to have it.
yes indeed
You need math when measuring ingredients. For example, think of doubling a recipe. You will need to double all the amounts of the ingredients. This requires math.
It's very doubtful it will make you sick. However, the baking powder will be useless in the recipe if it has reached (or surpassed) the expiration date.
The recipe that I use calls for baking soda.
yes
Baking soda will cause things to rise also. Muffins are smaller so there is not as much need for lift. Baking powder will give more rise than soda. Whoever created the recipe chose to use soda instead of baking powder.
Baking powder and baking soda are often used together in recipes in order to add lift to the final product. Because baking soda is a base and commercial baking powder is generally slightly acidic, they are often used together to neutralize both each other the other ingredients of the recipe. Yes baking powder and soda can both be used in the same recipe.
If you have too much baking powder, the muffin will look and taste different. If you have too little baking powder, the muffin will be all flat and taste different.