Chapter 7: Standardization Example | CHM 214 | 063
TLDRThe transcript describes a titration process for measuring calcium in urine by precipitating calcium oxalate, washing the precipitate, and dissolving it to form a solution of calcium and oxalic acid. The key step involves standardizing a permanganate solution using a primary standard of sodium oxalate. The molarity of the permanganate solution is calculated based on the stoichiometry of the reaction between oxalate and permanganate, ultimately determining the concentration of permanganate used in the titration.
Takeaways
- 🧪 The process involves measuring calcium in urine through a titration method.
- 🥄 Calcium is precipitated from urine using oxalate, forming calcium oxalate solid.
- 💧 The precipitate is washed with ice-cold water to remove excess oxalate.
- ⚗️ The solid is dissolved in acid to obtain a solution of calcium and oxalic acid.
- 🌡️ The oxalate in the solution is then titrated with a standardized permanganate solution.
- 📈 The endpoint of the titration is indicated by a purple color.
- 🔄 The first step is to standardize the permanganate solution using a primary standard like sodium oxalate.
- 📊 0.3562 grams of sodium oxalate is dissolved in a 250 mL volumetric flask for standardization.
- 📝 The molarity of the oxalate solution is calculated using its molar mass (134 g/mol) and the volume of the solution.
- 🌟 A 10 mL aliquot of the oxalate solution contains 0.01063 moles of oxalate per liter.
- 🔄 Based on stoichiometry, 5 moles of oxalate react with 2 moles of permanganate.
- 🎯 The concentration of the permanganate solution is determined to be 8.7947 × 10^-4 M.
Q & A
What is the main purpose of the titration process described in the transcript?
-The main purpose of the titration process described is to measure the concentration of calcium in urine by precipitating it as calcium oxalate and then analyzing the oxalate through titration with permanganate.
What is the role of oxalate (C2O4^2-) in this process?
-Oxalate (C2O4^2-) is used as a precipitating agent to convert calcium in the urine into a solid form, calcium oxalate, which can then be washed, dissolved, and prepared for titration.
How is the precipitate of calcium oxalate prepared for analysis?
-The precipitate is washed with ice-cold water to remove any excess oxalate, then dissolved in acid to obtain a solution of calcium and oxalic acid, ready for titration.
What is the significance of the permanganate solution in this titration process?
-The permanganate solution is used as the titrant to analyze the oxalate content. It is standardized and reacts with oxalate in a known stoichiometric ratio, allowing for the determination of the oxalate concentration.
How is the permanganate solution standardized?
-The permanganate solution is standardized by titrating it against a primary standard, such as sodium oxalate, and using the stoichiometry of the reaction to calculate the molarity of the permanganate solution.
What mass of sodium oxalate was used to standardize the permanganate solution in the example?
-In the example, 0.3562 grams of sodium oxalate were used to standardize the permanganate solution.
What is the molar mass of sodium oxalate?
-The molar mass of sodium oxalate is 134 grams per mole.
How is the concentration of the standard oxalate solution calculated?
-The concentration of the standard oxalate solution is calculated by dividing the mass of sodium oxalate (in moles) by the volume of the solution (in liters), resulting in a molar concentration.
What is the stoichiometric ratio between oxalate and permanganate in this titration?
-The stoichiometric ratio between oxalate and permanganate in this titration is 5:2, meaning 5 moles of oxalate react with 2 moles of permanganate.
What was the volume of potassium permanganate solution used to titrate 10 milliliters of the standard oxalate solution?
-48.36 milliliters of potassium permanganate solution were used to titrate 10 milliliters of the standard oxalate solution.
What was the calculated concentration of the permanganate solution after the titration?
-The calculated concentration of the permanganate solution was 8.7947 × 10^-4 molar.
Outlines
🧪 Titration Calculations: Measuring Calcium in Urine
This paragraph introduces a three-step process for measuring calcium in urine using titration calculations. It begins with precipitating calcium from urine using oxalate to form calcium oxalate. The precipitate is washed, dissolved, and then analyzed by titrating the oxalate with standardized permanganate solution, which changes color at the endpoint. The goal is to standardize the permanganate solution using a primary standard of sodium oxalate. The process involves calculating the molarity of the oxalate solution from the given mass, understanding the stoichiometry of the reaction, and ultimately determining the concentration of the permanganate solution used in the titration.
Mindmap
Keywords
💡Titration
💡Calcium Oxalate
💡Oxalate
💡Permanganate
💡Standardization
💡Molarity
💡Molar Mass
💡Stoichiometry
💡Endpoint
💡Volumetric Flask
💡Primary Standard
Highlights
The process described is a three-step titration method for measuring calcium in urine.
Calcium is precipitated from urine using oxalate, forming calcium oxalate solid.
The precipitate is washed with ice-cold water to remove excess oxalate.
The solid calcium oxalate is dissolved in acid to obtain a solution of calcium and oxalic acid.
The oxalate in the solution is then titrated with a standardized permanganate solution.
The endpoint of the titration is indicated by a purple color.
The permanganate solution must be standardized before the titration process.
A primary standard of sodium oxalate is used for standardizing the permanganate solution.
0.3562 grams of sodium oxalate is dissolved in a 250 milliliter volumetric flask.
10 milliliters of the sodium oxalate solution requires 48.36 milliliters of potassium permanganate for titration.
The molar mass of sodium oxalate is 134 grams per mole.
The concentration of the standard oxalate solution is calculated to be 0.01063 M.
A 10 mL aliquot of the standard oxalate solution contains 0.10063 millimoles of oxalate.
The stoichiometry of the reaction is such that 5 moles of oxalate react with 2 moles of permanganate.
The calculated millimoles of permanganate used in the titration is 0.04253.
The concentration of the permanganate solution is determined to be 8.7947 * 10^-4 M.
The method is useful for analyzing and measuring calcium levels in urine samples.
This titration process is an example of a practical application in analytical chemistry.
The procedure emphasizes the importance of accurate measurement and calculation in chemical analysis.
Transcripts
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