Chemistry BMAT- Separation Techniques Review Questions and Answers

what are physical differences that elements or compounds may have solubility mp/bp particle size or mass what is the difference between a miscible liquid and an immiscible liquid -miscible mix well with another to form a homogenous solution immiscible liquids cannot mix to give single phase. eg. water and oil as oil floats on top of water What is decantation? -process to seperate mixtures by removing a liquid layer that is free of a solid or another liquid can be used to seperate mixtures of IMMISCIBLE liquids or of a solid and liquid mixture such as a suspension what are the key terms in decanting -liquid that is collected is called the decant -solid left behind is called sediment how is a seperating funnel used and what is it used for -used for 2 immiscible liquids -added to seperating funnel form 2 layers -upper layer has LOWER DENSITY -when tap opened lower layer can be poured out when is distillation used to separate 2 substances with different boilig points when are evaporation and crystallisation used and how -used to separate solvent from solute -uses difference in boiling point and or volatility to separate mixture -in this it is SOLUTE wanted rather than solvent -gently heat until crystals become to appear what points should you consider when running the chromatogram -sample placed above solvent in tank so that it spread up with rising solvent rather than dissolves in solvent at bottom -use pencil line to mark position of sample line as pencil does not disllove in MOST SOLVENTS and so does not move -solvent front should not reach top of paper -lid to prevent solvent evaporation