Can self rising powder substitute for all purpose flour?

No, self-rising flour cannot completely substitute for all-purpose flour.

Here's why:

* Self-rising flour already contains leavening agents: These are baking powder and salt, which are designed to make the flour rise. If you use self-rising flour in a recipe that calls for all-purpose flour, you'll end up with too much leavening, resulting in a cake that's too airy or a bread that's crumbly.

* Self-rising flour has a lower protein content: This means it's not as good at forming gluten, which gives bread its structure and chewiness. If you use self-rising flour in a bread recipe, the bread might be too soft and flat.

What to do instead:

* Use all-purpose flour and add your own leavening agents: This is the most reliable way to get the right texture and rise.

* Use a recipe specifically designed for self-rising flour: Many recipes are specifically written for self-rising flour, so you can use it without any problems.

In summary: While you can sometimes get away with using self-rising flour in a recipe that calls for all-purpose flour, it's not ideal. It's best to stick to the recipe's instructions or find a recipe specifically designed for self-rising flour.