What is the endpoint for phenolphthalein indicator, chemistry homework help

What is the endpoint for phenolphthalein indicator?

2. Is there a direct relationship between pH and Titratable Acidity?

3. Which method is more sensitive to small changes in acidity?

4. Why is pH measurement so important in regard to foodstuffs?

5. Traditionally, buttermilk was the liquid left behind after churning butter out of cream. Outline the modern method of buttermilk production with reference to pH.

6. How would titratable acidity be expressed for apple juice?