use yeast or sourdough culture. baking soda is the more simple and basic bread leavener. the alternative would be to use no leavener at all for your bread, such as matzoh, tortillas, crackers,...
It depends what you are making because if it if some sort of cake like cupcakes for example they will deflate if it is a pie of some sort then it may taste different.
Yes, in many recipes baking powder can be successfully substituted for baking soda. The product might not rise as well but should be satisfactory. It is NOT recommended to reverse the substitution,...
Baking powder has two active ingredients: Cream of tartar (tartaric acid) and baking soda (sodium bicarbonate). The reaction of these two creates a salt and a gas, (carbon dioxide) which, as it is...