Acid-Base Reactions and Indicators

The video tutorial demonstrates a neutralization reaction using sodium hydroxide, hydrochloric acid, and phenolphthalein. Initially, sodium hydroxide is colorless, but turns pink when phenolphthalein is added. As hydrochloric acid is added, the pink color fades, indicating neutralization. When more sodium hydroxide is added, the pink color reappears, showing the reaction between acid and base, forming salt and water.

What materials are required to perform the neutralization reaction experiment?

• Sodium chloride, water, and phenolphthalein

• Dilute hydrochloric acid, sodium hydroxide solution, and phenolphthalein

• Sodium bicarbonate, vinegar, and phenolphthalein

• Sulfuric acid, sodium hydroxide, and methyl orange

What is the initial observation when sodium hydroxide is transferred to the conical flask?

• The solution turns blue

• The solution remains colorless

• The solution becomes cloudy

• The solution turns pink

What happens when phenolphthalein is added to the sodium hydroxide solution?

• The solution turns blue

• The solution remains colorless

• The solution turns green

• The solution turns pink

Why does the solution turn pink when phenolphthalein is added?

• Because phenolphthalein turns pink in an acidic solution

• Because phenolphthalein is a basic solution

• Because phenolphthalein is an acidic solution

• Because phenolphthalein turns pink in a basic solution

What is the role of phenolphthalein in the experiment?

• It acts as a solvent

• It acts as an indicator

• It acts as a catalyst

• It acts as a reactant

What is observed when hydrochloric acid is added to the pink solution?

• The pink color intensifies

• The pink color disappears

• The solution becomes cloudy

• The solution turns blue

Why does the pink color disappear when hydrochloric acid is added?

• Because the solution becomes more basic

• Because the solution becomes neutral

• Because the solution becomes acidic

• Because the solution becomes saturated

What happens when more sodium hydroxide is added to the acidic solution?

• The solution turns blue

• The pink color reappears

• The solution remains colorless

• The solution becomes cloudy

What are the products formed when sodium hydroxide reacts with hydrochloric acid?

• Sodium bicarbonate and water

• Sodium sulfate and water

• Sodium chloride and water

• Sodium acetate and water

What type of reaction occurs when an acid reacts with a base?

• Redox reaction

• Neutralization reaction

• Decomposition reaction

• Combustion reaction