You can use baking powder in baking if you don't have baking soda.
When using baking powder in place of baking soda when you don't have baking soda you just use 3 times as much of baking powder to replace baking soda with.
For example if a recipe calls for one teaspoon of baking soda, you instead would use three teaspoons of baking powder.
And since baking powder contains a little salt you should also halve the salt the recipe calls for.
Baking soda and baking powder are not the same although they can be used in place of one another in recipes.
Sodium bicarbonate and bicarbonate of soda are other names for baking soda.
Baking powder is made of baking soda plus cream of tartar and cornstarch.
Just remember that baking soda is stronger than baking powder, so you'll want to use a quarter of the amount of baking soda as powder.
So if the recipe calls for 1 tsp. baking powder, use ΒΌ tsp. baking soda.