Answer:
3. turns pink and is basic
Explanation:
Phenolphthalein is a pH indicator that remains colorless in acidic solutions, but in basic solutions it turns pink at a pH equal to 10.
Phenolphthalein is a weak acid that loses H+ cations in solution. The phenolphthalein molecule is colorless, while the phenolphthalein-derived anion is pink. When a base is added, phenolphthalein loses H+, forming the anion and causing it to turn pink. The color change cannot be explained only on the basis of deprotonation, a structural change occurs with the appearance of a ketoenolic tautomerism.
Concentration can be expressed in different forms: molarity, molality, normality, percentage, part per million and many more. For molality, it is a unit of concentration expressed as moles of solute per kilogram of solvent. Therefore,
0.3 = moles solute/0.10 kg solvent
moles solute = 0.03 moles