Question

Как изменится окраска фенолфталеина в растворе пищевой соды и почему?

Answer 1

В растворе пищевой соды, фенолфталеин будет иметь малиновую окраску. Потому, что водный раствор пищевой соды имеет щелочную среду.

Answer 2

Effect of Sodium Bicarbonate on Phenolphthalein Color Change

When phenolphthalein is added to a solution of sodium bicarbonate, the color change occurs due to the change in pH level. Phenolphthalein is a pH indicator that changes color in response to the acidity or basicity of a solution.

Phenolphthalein in Acidic and Basic Solutions: - In acidic solutions, phenolphthalein remains colorless. - In basic solutions, phenolphthalein turns pink or magenta.

Reaction with Sodium Bicarbonate: - When phenolphthalein is added to a solution of sodium bicarbonate, which is a basic (alkaline) substance, the pH of the solution increases. - This increase in pH causes the phenolphthalein to change color from colorless to pink or magenta.

Explanation: - The reaction can be explained by the fact that sodium bicarbonate (NaHCO3) is a weak base. When it dissolves in water, it releases bicarbonate ions (HCO3-) and sodium ions (Na+). - The bicarbonate ions react with water to form carbonic acid (H2CO3), which then dissociates to release hydrogen ions (H+) and bicarbonate ions (HCO3-). - The increase in the concentration of hydroxide ions (OH-) from the dissociation of bicarbonate ions causes the solution to become more basic, leading to the color change in phenolphthalein.

Conclusion: - In summary, the addition of phenolphthalein to a solution of sodium bicarbonate causes a color change from colorless to pink or magenta due to the increase in pH, making the solution more basic.

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