Mention 5 laboratory procedure that can be used to identify purity of a substance?

1. Melting point determination: This procedure involves measuring the temperature at which a substance changes from a solid to a liquid state. A pure substance will have a sharp and well-defined melting point, while impurities can cause a depression or broadening of the melting point range.

2. Boiling point determination: Similar to melting point determination, this procedure involves measuring the temperature at which a substance changes from a liquid to a gas state. A pure substance will have a specific and consistent boiling point, while impurities can cause the boiling point to increase or the boiling range to broaden.

3. Chromatography: This technique separates the components of a mixture based on their different affinities for a stationary phase and a mobile phase. By comparing the separation pattern of a sample with that of a pure substance, the presence of impurities can be detected.

4. Spectroscopy: Various spectroscopic techniques, such as infrared spectroscopy, ultraviolet-visible spectroscopy, and nuclear magnetic resonance spectroscopy, can be used to analyze the absorption or emission of electromagnetic radiation by a substance. These techniques can provide information about the molecular structure and functional groups present, helping to identify impurities.

5. Elemental analysis: This procedure involves determining the elemental composition of a substance. Techniques such as elemental analysis by combustion or spectroscopic methods like X-ray fluorescence can be used to quantify the amounts of different elements present. Deviations from the expected elemental composition can indicate the presence of impurities.