Titration Techniques and Concepts

Katie, a PhD student, demonstrates a titration experiment to determine the concentration of an unknown acid. She begins by explaining safety measures, then prepares the pipette and sets up the burette. The titration involves adding sodium hydroxide to ethanoic acid and observing a color change. Lucy explains the science behind the reaction, including the concept of pH, neutralization, and the importance of accurate measurements. The experiment concludes with calculating the concentration of ethanoic acid using the titration results.

What is the first safety step Katie takes before starting the experiment?

• Setting up the burette

• Washing the pipette

• Tying her hair up

• Adding phenolphthalein

What is the purpose of adding phenolphthalein to the beaker?

• To increase the pH

• To indicate the end point of the titration

• To act as a catalyst

• To neutralize the solution

Why is it important to ensure there are no bubbles in the burette?

• Bubbles increase the reaction rate

• Bubbles change the color of the solution

• Bubbles are necessary for the reaction

• Bubbles can cause inaccurate volume readings

During the titration, what indicates that the reaction is complete?

• The solution turns dark pink

• The solution starts boiling

• The solution remains light pink

• The solution becomes colorless

What is the pH range of acids?

• Exactly 7

• Less than 7

• Equal to 7

• More than 7

What is the role of sodium hydroxide in the titration?

• It is the solvent

• It is the indicator

• It acts as a base

• It acts as an acid

What is the concentration of sodium hydroxide used in the experiment?

• 0.5 moles per liter

• 0.2 moles per liter

• 0.1 moles per liter

• 0.05 moles per liter

What is the ratio of moles of ethanoic acid to sodium hydroxide in the reaction?

• 2:2

• 1:1

• 2:1

• 1:2

How is the concentration of ethanoic acid determined after the titration?

• By observing the color change

• By weighing the solution

• By using the volume of sodium hydroxide

• By measuring the pH

What is the final calculated concentration of ethanoic acid?

• 0.1 moles per liter

• 0.09 moles per liter

• 0.07 moles per liter

• 0.05 moles per liter