Titrations — Precision Quantitative Analysis
11 experiments
Titration is a quantitative analytical technique that determines the concentration of an unknown solution by reacting it with a solution of known concentration (the titrant). The endpoint — where the reaction is complete — is detected by an indicator color change, pH meter, or conductivity change. Titrations are the backbone of analytical chemistry in quality control laboratories worldwide.
Learning Objectives
Students master volumetric analysis: precise measurement with burettes, stoichiometric calculations, endpoint detection, and error analysis. Acid-base titrations teach neutralization; redox titrations (permanganate, iodometric) teach electron-transfer stoichiometry. Complexometric titrations with EDTA determine water hardness.
Key Techniques
Rinse the burette with titrant before filling. Swirl the flask during addition. Approach the endpoint dropwise, then half-drops. Record the volume at the meniscus bottom for clear solutions, top for dark solutions. Back-titration is used when the analyte reacts slowly or is insoluble — add excess reagent, then titrate the unreacted portion.
Equipment Overview
Required: burette (25 or 50 mL, Class A), burette clamp and stand, Erlenmeyer flask, volumetric pipette, wash bottle, indicator solutions. Digital burettes eliminate parallax error. Automatic titrators with pH electrodes provide continuous monitoring and computer-plotted titration curves.
Acid-Base Titration with Methyl Orange
Titrating a weak base with a strong acid
Determine the concentration of a sodium carbonate solution by titrating it with hydrochloric acid using methyl orange indicator, suitable for …
Acid-Base Titration with Phenolphthalein
Determining the concentration of an acid using a standard base
Determine the concentration of an unknown hydrochloric acid solution by titrating it with a standardized sodium hydroxide solution, using phenolphthalein …
Back Titration of Antacid Tablets
Measuring the acid-neutralizing capacity of commercial antacids
Determine the acid-neutralizing capacity of a commercial antacid tablet using a back titration method.
Conductometric Titration
Tracking a titration using electrical conductivity
Perform an acid-base titration using conductivity measurements instead of an indicator, and determine the endpoint from a conductivity-volume graph.
Double Indicator Titration of Carbonate-Bicarbonate Mixture
Using two indicators to analyze a carbonate mixture
Analyze a mixture of sodium carbonate and sodium bicarbonate by titrating with HCl using two indicators sequentially: phenolphthalein and methyl …
EDTA Complexometric Titration of Water Hardness
Measuring calcium and magnesium content in water
Determine the total hardness of a water sample by titrating dissolved Ca2+ and Mg2+ ions with EDTA using Eriochrome Black …
Iodometric Titration of Bleach
Determining the concentration of sodium hypochlorite in household bleach
Determine the sodium hypochlorite (NaOCl) concentration in commercial bleach using iodometric titration with sodium thiosulfate.
pH Titration Curve
Plotting a complete acid-base titration curve with pH meter
Record pH measurements during an acid-base titration and construct a complete S-shaped titration curve showing the equivalence point and buffer …
Precipitation Titration (Mohr Method)
Determining chloride concentration using silver nitrate
Determine the chloride ion concentration in a solution using the Mohr method, where silver nitrate is the titrant and potassium …
Redox Titration with Potassium Permanganate
Determining iron(II) concentration using KMnO₄
Determine the concentration of an iron(II) sulfate solution by titrating with standardized potassium permanganate, a self-indicating reagent.
Vitamin C Titration with Iodine
Measuring ascorbic acid content in fruit juice
Determine the vitamin C (ascorbic acid) content of fresh fruit juice using an iodine titration with starch indicator.