Cooking blunder

I am just in the process of making some Christmas presents - a great idea where you put dry ingredients in a jar for a muffin mix or something of the like and add a recipe for the wet ingredients.

They mainly use plain flour and baking powder. So, a small question to you budding cooks out there... what happens when you put cream of tartar in, instead of the baking powder??

Hmmm, I am thinking maybe that maybe McKenzie's should take 'Baking' off the front of the label of all these types of ingredients in the same shaped container. It can get very confusing!!