Burette
Burette - Related Videos
13:26
Solubility - Student Protocol
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2020
Source: Smaa Koraym at Johns Hopkins University, MD, USA Creating a Saturated SolutionExpand In this experiment, you will create a saturated solution of sodium tetraborate decahydrate, also called borax. In water, borax dissociates into two sodium cations and one tetraborate anion. When an aqueous borax solution is saturated, it means that it contains the maximum amount of dissolved solute, which is borax, for that volume of solvent, which is water. Any additional solid won't appear to...
02:58
Solubility - Instructor Prep
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2020
Source: Smaa Koraym at Johns Hopkins University, MD, USA Lab Preparation for Determining the Solubility of BoraxExpand Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed. Assign each of the lab groups a temperature of either 10, 20, 30, 40, or 50 °C. Note: There can be duplicates for larger class sizes. Place a stock bottle of borax, weighing boats, and a spatula at each weigh station. Prepare...
14:48
Acid and Base Concentrations - Student Protocol
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2020
Source: Smaa Koraym at Johns Hopkins University, MD, USA Preparation of ~0.1 M NaOHExpand In the first part of the lab, you will use a 50% w/w solution of NaOH to prepare 500 mL of ~0.1 M. The 50% w/w NaOH is indicative of its weight ratio. For example, if the instructor prepared 150 mL of the 50% w/w NaOH solution, then 150 g of NaOH was dissolved in 150 g of water, and the total weight of the solution is 300 g. To begin, put on the appropriate personal protective equipment,...
17:02
Beer's Law - Student Protocol
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2020
Source: Smaa Koraym at Johns Hopkins University, MD, USA Lab Setup for Beer’s LawExpand In this lab, you will combine aqueous solutions of FeCl3 and NaSCN to form an orange-red [Fe(NCS)]2+ complex. When FeCl3 is dissolved in water, the iron center is surrounded by six water molecules. This acidic complex easily loses protons from its water molecules, which can lead to iron hydroxides precipitating from solution. To prevent this, your solutions will include enough HNO3 to keep the iron in...
10:17
Introduction to Titration
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2023
Source: Laboratory of Dr. Yee Nee Tan — Agency for Science, Technology, and Research Titration is a common technique used to quantitatively determine the unknown concentration of an identified analyte.1-4 It is also called volumetric analysis, as the measurement of volumes is critical in titration. There are many types of titrations based on the types of reactions they exploit. The most common types are acid-base titrations and redox titrations.5-11 In a typical titration process, a standard...
FAQs
The stopcock regulates how quickly solution leaves the narrow tube, allowing the analyst to control delivery while approaching the reaction endpoint. This controlled flow matters because the final volume must correspond closely to the indicator color change. By adjusting the stopcock rather than releasing the entire solution at once, the analyst can monitor the reaction and record a meaningful endpoint volume.
The delivered volume is obtained from the difference between the final and initial meniscus readings, not from either reading alone. Using both values accounts for the starting liquid level and identifies how much solution actually left the instrument. This difference becomes the measured quantity used in the subsequent quantitative chemical analysis.
The indicator endpoint provides a visible stopping point for liquid delivery, usually through a color change associated with the reaction. The analyst records the burette reading when that change occurs, then relates the delivered volume to the known concentration of one reactant. This connects an observable laboratory event with the concentration calculation.
The measured volume dispensed from the burette is combined with the known concentration of one reactant to calculate the concentration of another. The calculation therefore depends on both a reliable volume difference and the chemical reaction being analyzed. This relationship allows titration to convert controlled liquid delivery into quantitative information about an unknown solution.
A basic workflow establishes the starting meniscus reading, delivers the solution through the stopcock while the reaction proceeds, and records the final meniscus reading when the indicator reaches its endpoint color. The difference between the two readings gives the volume used. That volume is then combined with the known reactant concentration for analysis.
Burette measurements support acid-base, redox, and complexometric titrations. Although these analyses involve different chemical reaction types, each uses controlled solution delivery and a measured volume at the reaction endpoint. This versatility makes the instrument relevant to several areas of quantitative chemistry rather than limiting it to acid-base experiments.
Burette-based titrations are used in quality control, environmental testing, and pharmaceutical analysis. In each setting, the measured volume helps determine the concentration of a substance through a chemical reaction with a known reactant. The resulting quantitative information can support analysis of materials, samples, or products, while instructional laboratories use the same principle to teach chemical measurement.
In instructional laboratory work, a burette connects several core skills: controlled solution delivery, meniscus reading, endpoint recognition, and concentration calculation. Students can observe how a reaction endpoint produces a measurable volume and how that volume supports quantitative analysis. The instrument therefore links practical measurement technique with the chemical reasoning required to determine an unknown concentration.