What methods can be used to test the purity of an organic solid? Explain how these methods work.

The purity of an organic solid can be tested by measuring its melting point and comparing it to the literature value. A pure substance has a sharp melting point, while impurities lower and broaden the melting point range. Thin-layer chromatography (TLC) can also be used to assess purity by comparing the number of spots obtained from the sample with those of pure compounds. This answer is anchored to A-level required practical activities.

The purity of an organic solid can be tested by measuring its melting point and comparing it to the literature value. A pure substance has a sharp melting point, while impurities lower and broaden the melting point range. Thin-layer chromatography (TLC) can also be used to assess purity by comparing the number of spots obtained from the sample with those of pure compounds. is the best answer because it directly supports the AQA A-Level Chemistry objective to required practical 10: prepare an organic solid and test its purity. This reasoning is anchored to A-level required practical activities in A-level practical endorsement and required practical activities, and it separates required practical from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.