If insoluble impurities eg. dust, tissues, filter paper etc were mixed with the sample how will these affect the measured melting point

4. A student received an impure sample of benzoic acid and reported the melting "mp=121.5 °C." The student reported the sample as pure since the melting too far off. What mistake was made that could have proven the sample's point as wasn't point impurity?

An ideal property of a solvent to be suitable for recrystallization of a solid sample is: Group of answer choices To have a high boiling point. To dissolve the solid at room temperature but not in cold temperature. To react with the solid to be recrystallized. To dissolve the solid at the solvent's boiling temperature but not at room or cold temperature.

a. Colloidal particles typically have a negative surface charge that attracts oppositely charged positive ions in the surrounding bulk solution. These so-called _______-ions are held at the particle surface through electrostatic and van der Waals forces of attraction strongly enough to overcome thermal agitation. b. Turbine and propeller type mechanical mixers used for rapid mixing of reagent chemicals have either ------------- flow impellers with flat or curved blades located parallel to the axis of the drive shaft, or --------------------- flow impellers with blades making an angle of less than 90o with the drive shaf