- What is the importance of knowing the melting point of a natural compound after extraction? Below are the results you got from your experiment (Caffein extraction from tea leaves). The melting point of caffeine was reported to be around 238 °C in literature. Discuss the reason(s) for getting higher or lower melting point than 238 °C from your experiment.
Melting point is property of substances. The solid phase substance changes to the liquid phase at this temperature. The melting point of a substance is often determined by the amount of energy required to break the bonds, which hold the compound in its 3-dimensional structure, therefore, a high melting point is the result of a greater amount of energy required to break down the 3-dimensional structure. Often the melting point of a sample is used to characterise the compound and determine the purity of the compound. Pure substances often melt at a high-defined temperature. Therefore, when measuring the melting point of natural compounds, which have been extracted, it is important to make sure the melting point of the extract is what was expected. Variances at the melting point would imply that the extracted compound is not at its purest and could result in unforeseen complications when refined further and could result failure to meet regulations both nationally and internationally. When assessing the melting point of our caffeine extract we notice that the observed melting point temperature 236˚C was less than the expected literature temperature of 238˚C. A reason as to why our melting point was lower than expected may have been a result of impurities or solvents present in the sample we produced. The impurity may have caused a decrease in melting point as it could have altered the compound lattice and therefore, reducing the energy required to break the structural bonds present in the compound lattice.
