Answer is: <span>(CH3)C.
Carbon has four bonds in organic compound.
1) in </span>(CH3)CH, carbon has four single bonds, one with hydrogen and three witn methyl group (CH₃), <span>so he is not radical.
2) in </span><span>(CH3)C, carbon has three single bonds and one free electron.
3) in </span>(CH3)C+, carbon has three single bonds and no free electrons, he is carbocation, not radical.
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).
Answer:
the mixture or solution is called homogeneous mixture