Here's why:
* Paraffin's Melting Point is Too Low: Paraffin wax has a melting point around 47-65°C (117-149°F). This range is too low for most common organic compounds and would not provide accurate results for substances with higher melting points.
* Paraffin is Not Chemically Inert: Paraffin is a hydrocarbon and can interact with some substances, potentially altering their melting point or causing contamination.
* Lack of Precision: Paraffin is not a precise standard for melting point determination. Its melting point can vary depending on the source and purification process.
What is used for melting point determination?
The standard method for determining the melting point of a substance involves using a melting point apparatus. This typically uses a heating block or a capillary tube filled with the substance, which is then slowly heated while the temperature is observed. The melting point is recorded as the temperature at which the solid substance transitions to a liquid.
Here are some common substances used as reference standards for calibration of melting point apparatus:
* Benzoic acid: Melting point of 122.4°C
* Naphthalene: Melting point of 80.2°C
* Phenacetin: Melting point of 135°C
In conclusion, paraffin is not suitable for determining melting points due to its low melting point and potential for interaction with the substance being tested. A calibrated melting point apparatus and appropriate reference standards are used for accurate determination.
