【Daily Question】June 7, 2018: +2 wealth for participation； +3 to +10 wealth for correct answers
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Fill-in-the-blank: When 1–2 drops of phenolphthalein indicator are added to deionized water commonly used in laboratories, the water should appear ( ). Colorless
When phenolphthalein turns red, the pH is close to 10. Due to the presence of CO2 in the air, the solution absorbs carbon dioxide, causing the pH to drop below 8; and when the pH is below 8, the phenolphthalein indicator becomes colorless. Methyl orange is yellow at high pH and orange-red at low pH...