1. What is a 25 ml Volumetric Flask?

Definition: A 25 ml volumetric flask is a precision laboratory glassware designed to contain exactly 25 milliliters of liquid at a specified temperature.

Purpose: Used for preparing accurate standard solutions and precise dilutions in analytical chemistry and other scientific applications.

2. Key Features

• Calibrated to contain (TC) exactly 25 ml at 20°C (standard temperature)
• Features a single graduation mark on the neck
• Made of borosilicate glass for thermal and chemical resistance
• Typically has a glass or plastic stopper

3. Proper Use of Volumetric Flasks

Details: For accurate measurements, the bottom of the meniscus should align exactly with the graduation mark when viewed at eye level.

4. Verification

Tips: Enter the volume value to verify if it matches the standard 25 ml specification. The flask should be clean and at the correct temperature (usually 20°C).

5. Frequently Asked Questions (FAQ)

Q1: Why is temperature important for volumetric flasks?
A: Glass expands and contracts with temperature, affecting the actual contained volume. Calibration is typically done at 20°C.

Q2: Can I heat liquids in a volumetric flask?
A: No, volumetric flasks are not designed for heating. Use an Erlenmeyer flask or beaker for heating applications.

Q3: How accurate is a 25 ml volumetric flask?
A: Class A flasks typically have ±0.03 ml tolerance, while Class B have ±0.06 ml tolerance at 20°C.

Q4: How should I clean a volumetric flask?
A: Use appropriate solvents and brushes, rinse thoroughly with distilled water, and never dry by heating.

Q5: Can I use a 25 ml flask for other volumes?
A: No, volumetric flasks should only be used at their specified volume for accurate measurements.