Is baking powder used in baking soda?

Baking powder is not the same as baking soda.

Baking powder is a 1:3 ratio of baking soda to cream of tartar, which are both raising agents designed for different purposes - one of them is activated by water, the other by heat.

Baking soda is "strong" compared to baking powder, and is not a direct substitute for baking powder.