A. True. The addition of impurities interfer with the ability to form crystaline structures and cause liquids to remain until colder temperaturs, much like putting salt on the roadways. B) True. the compounds will demonstrate a fuzzy melting point when impurities are present, when they are not present the temp sreads throughout the substance and it will seem to convert to a liquid rapidly at a single temperqature rather than over a couple degrees. C) True. the melting point of the addition is not very important as long as it is a minority component. The presence of impurities in the solid crystaline structure lowers the melting point, salt melts at a much higher temp than water, yet lowers the melting point of water, same principal even though water and salt are both inorganic. if the substance is identical then there is not an effect of an impurity being present and the mp is unchanged. D) true for the same reasons, impurities lower melting point. if enough of substance b was added that it became the solvent, mp of solution could rise but it would be lower than substance b mp. Solution A. True. The addition of impurities interfer with the ability to form crystaline structures and cause liquids to remain until colder temperaturs, much like putting salt on the roadways. B) True. the compounds will demonstrate a fuzzy melting point when impurities are present, when they are not present the temp sreads throughout the substance and it will seem to convert to a liquid rapidly at a single temperqature rather than over a couple degrees. C) True. the melting point of the addition is not very important as long as it is a minority component. The presence of impurities in the solid crystaline structure lowers the melting point, salt melts at a much higher temp than water, yet lowers the melting point of water, same principal even though water and salt are both inorganic. if the substance is identical then there is not an effect of an impurity being present and the mp is unchanged. D) true for the same reasons, impurities lower melting point. if enough of substance b was added that it became the solvent, mp of solution could rise but it would be lower than substance b mp..