Arrangements of Matter
Impure Substances
A homogeneous substance is a substance from which all samples taken will have the same properties
A heterogeneous substance is a substance from which all samples taken will not have the same properties.
A pure substance has one melting point and one boiling point, whereas an impure substance will have different melting and boiling points for each of the different molecule within it.
Phases
Definitions
Solute: The minor component in a solution, dissolved in the solvent.
Solvent: The liquid in which a solute is dissolved to form a solution.
Phase: A physically distinctive form of matter with uniform properties
Suspension: A state in which larger particles are dispersed throughout a fluid, which eventually settle and form layers.
Colloid: A state in which smaller particles are dispersed throughout a fluid.
Gel: A dispersion of liquid molecules in a solid.
Emulsion: A mixture with two substances that originally don’t mix but bind together with the aid of a chemical agent (emulsifier).
Miscible V/S Immiscible
Miscible substances are substances that are able to form a solution with one another, whereas immiscible substances cannot.
Emulsifiers
An emulsifier is a chemical agent that is used to make immiscible substances form a solution. This is done by binding the two substances to different ends of the emulsifier.
For example, water and oil are immiscible, but if one end of an emulsifier bonds to water (hydrophilic end) and the other bonds to oil (hydrophobic end) then a solution will be made.
Separating Substances
Definitions
Filtrate: The product of filtration
Residue: What is left after filtration takes place.
Distillate: The vapor collected in distillation which is then cooled to form a liquid.
Volatile: When a substance can easily undergo a change from liquid into a gas.
Methods of Separation
Decantation: Separating a solid + liquid mixture by pouring out the liquid and leaving only the solid.
Evaporation: Heating up a solution so that the solvent of the solution evaporates and leaves the solute in the container.
Vaporization: Heating up the solid/liquid to turn it into a gas.
Filtration: Using a funnel and filter paper over a beaker, place a solid + liquid mixture in the funnel, and only the liquid will pass through.
Separation Funnel: Place a suspension of 2 liquids in a separation funnel, the higher density liquid will sink to the bottom and will flow through the funnel.
Distillation: Attached to a Liebig condenser with cold flowing water, heat up (its boiling point) mixture and collect the condensed vapor on the other end of the Liebig condenser. For example, take a solution of alcohol and water, with a boiling point of 70 and 100 degrees respectively. In order to separate the two solutions, the mixture is heated to boiling point. Alcohol will soon reach the boiling point and will evaporate. Leaving behind water molecules. The evaporated solution is condensed and collected through a Liebig condenser. Hence both elements are separated.
Chromatography: Place a small spot of the ink \(2 \mathrm{~cm}\) from the bottom of a piece of paper, and suspend the paper so that the bottom \(1 \mathrm{~cm}\) is in the water in a beaker.
Retardation Factor
The retardation factor is the distance moved by the sample divided by the distance moved by the solvent (water).
Dialysis
Definitions
Diffusion: When a fluid moves from an area of high concentration to an area of low concentration.
Osmosis: When a solvent (water) moves from an area of high concentration to an area of low concentration through a semi – permeable membrane.
Semi – permeable: A barrier that only allows certain substances to go through it.
Dialysate: The part of a mixture that flows through the membrane in dialysis.
Process
1. Either the bloodstream gets connected to a dialysis machine or a dialysis fluid is pumped into the abdominal area.
2. The machine or the dialysis fluid diffuses out the toxins from the blood into it through osmosis.
3. Since the toxin is a solvent, and there is a lower concentration of the toxin in the dialysis fluid or the machine, then osmosis takes place.