In the video the presenter very briefly mentions further purification of the final product. (a). Explain why a further purification is needed (Hint: Think about the analysis). (b). Identifying a suitable solvent, name a method for further purification of the final product.

In what way do investigations build scientific knowledge? the results of investigations lead to questions that cannot be tested. they reflect the opinions and social values of scientists, ensuring valid information. the results of investigations lead to new questions, which lead to new investigations. they are not influenced by the research of earlier scientists, so they are able to address gaps in understanding.i