Answer is: a) in the presence of a base.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄).
When solution turns phenolphthalein pink, it means it is basic (pH>7).
They do this so that when you drink it or use it the contaminates that used to be in it dont make you sick
Eight because an octet has 8 electrons and when it’s full it’s stable. If it’s not full, it’s constantly sharing or borrowing electrons.
Answer:
<h2>7.54 atm </h2>
Explanation:
The required pressure can be found by using the formula for Boyle's law which is

where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
From the question we have

We have the final answer as
<h3>7.54 atm </h3>
Hope this helps you