Press "Enter" to skip to content

Why is phenolphthalein pink in basic solution?

Why is phenolphthalein pink in basic solution?

Phenolphthalein, an acid-base indicator used to test the pH of a solution, turns pink due to the presence of a weak base. The indicator itself is a weak, colorless acid that forms pink anions when it dissolves in water. Although the anions are pink, the solution remains colorless in the presence of an acid.

When a drop of phenolphthalein is added to solution a it turns pink .the Solution A is?

(b) Solution A gives pink colour when a drop of phenolphthalein indicator is added, therefore A is a base. Solution B gives red colour when a drop of methyl orange is added to it, therefore B is an acid. Hence, solution A will have less concentration of hydrogen ion than B.

What happens when two drops of phenolphthalein are added to a dilute solution of NaOH?

Phenolphthalein remains colourless in neutral or acidic solution but turns out magenta or pink in basic solutions. When it is added to NaOH, the solution has the colour of pink since sodium hydroxide is a strong base.

What happens when a few drops of phenolphthalein is added to dilute NaOH?

When a few drops of phenolphthalein are added to a dilute solution of sodium hydroxide, a pink colour is produced. On adding excess of HCl, the solution will become acidic and the solution will change colour from pink to colourless.

What would be the Colour of Naoh solution when phenolphthalein indicator is added?

A few drops of phenolphthalein indicator are added. (b) The solution containing sodium hydroxide in an unknown concentration is added until a faint pink color is visible for a few seconds….

Indicator Color in acid Color in base
phenolphthalein colorless pink
methyl orange red yellow
bromothymol blue yellow blue

wHat happens if ammonia gas is passed into water containing a few drops of phenolphthalein solution?

Ans: When ammonia gas is passed into water containing few drops of phenolphthalein, the water turns into pink colour due to the formation of alkali (ammonium hydroxide).

wHat happens when phenolphthalein is added to acidic solution basic solution and neutral solution Class 7?

Hint: In a neutral solution, the phenolphthalein would give a light pink colour. When phenolphthalein is added to the base the colour of the solution intensifies and if it is added to an acidic solution the colour will fade away and become colourless.

What happens when phenolphthalein is added to Naoh?

Explanation: When the sodium hydroxide, which is a base, is mixed with phenolphthalein, it turns pink. This happens because the base is neutralized in an acid solution, which causes the indicator to become colorless. All of the base is neutralized by the citric acid.

What happens when an acid is added to a solution?

Adding an acid increases the concentration of H3O+ ions in the solution. Adding a base decreases the concentration of H3O+ ions in the solution. An acid and a base are like chemical opposites. If an acid is added to a basic solution, the solution becomes less basic and moves toward the middle of the pH scale.

What happens when phenolphthalein is added to HCL?

Answer. Phenolphthalein is a weak acid, which is why when it is added in a strong base, it gives pink color and the color gets intense as the PH of the base increases. By adding HCL in the solution, the pink color of phenolphthalein will disappear. This is also called Acid- Base Titration.

What is the Colour of phenolphthalein in HCl?

colourless

Why did the Colour of the solution change after adding the HCl solution?

Why did the colour of the solution change after adding the HCl solution? The pink colour of the solution of NaOH to which phenolphthalene is added be-comes colourless after adding dilute HCl because HCl is an acid and phenolphthalene becomes colourless in acid medium.

What is the color of dilute HCl?

Red