Titration Fundamentals Quiz

Titration Fundamentals

• Titration is a method for determining the concentration of an unknown solution by using a solution of known concentration.
• It measures the volume delivered from a buret during the process.

Buret Overview

• A buret is a graduated glass tube equipped with a tap for precise liquid delivery.
• In this lab, sodium hydroxide is contained in the buret, with the tap being vertical when open and horizontal when closed.

Equipment Definitions

• Stopcock (or petcock) is used to control the flow of liquid through tubing, specifically the tap on the buret.
• To read a buret correctly, note that the smallest numbers are on top, indicating liquid volume released when measuring bottom-to-top.

Chemical Components

• Acetic acid (vinegar) is represented by the formula HC₂H₃O₂ or CH₃COOH.
• Sodium hydroxide (NaOH) is a strong base used in the titration process.

Key Titration Points

• The endpoint is reached when the indicator changes color, signaling the stopping point of titration.
• The equivalence point occurs when the acid and base have fully reacted, indicating complete neutralization.

Potential Errors

• Titration error arises if the endpoint does not closely match the equivalence point, affecting accuracy.

Indicators and Their Role

• An indicator changes color in response to an acid or base; phenolphthalein is used, turning red-pink in basic conditions and remaining colorless in acidic.

Dilution Process

• Dilution involves adding a solvent to decrease solute concentration; sodium hydroxide is diluted for titration yet should be standardized for precise concentration.

Required Materials for Lab

• Essential materials for the lab include a buret, pipet, pipet filler, Erlenmeyer flask, clamp, ring stand, stopcock, funnel, and distilled water.

Safety Note

• Sodium hydroxide is caustic; precautions should be taken to ensure skin contact is avoided and correct handling is practiced.

Lab Introduction

• The titration experiment uses sodium hydroxide to neutralize an acetic acid (vinegar) solution, identified by phenolphthalein's color changes signaling the endpoint.

Lab Procedure Steps

• Measure a 10.00 mL sample of vinegar, add phenolphthalein indicator, and prepare the buret with sodium hydroxide solution.
• Record initial buret volume, then slowly add sodium hydroxide to the acid while swirling to mix, tracking the endpoint indicated by color change.