Solution- A well mixed mixture that contains a solvent and at least one solute.( may be made of any combo of gases, liquids and solids)
Solvent- Is the part of a solution present in the largest amount. It dissolves the other substance. (often water - universal solvent)
(gasoline, another solvent)
Solute- The substance that is present in a solution in a smaller amount and is dissolved by the solvent.
Colloid- A mixture containing small, undissolved particles that do not settle out. (gelatin, fog, milk, mayo, shaving cream, whipped cream)
Suspension- A mixture in which particles can be seen and easily separated by settling or filtration. (pepper & water)
Dilute Solution- a mixture that has only a little solute dissolved in a certain amount of solvent. (juice that has added water to the concentrated form)
Concentrated Solution- a solution that has a lot of solute dissolved in the solvent. (sap vs maple syrup)(fruit juices - concentrate)
Solubility- Is a measure pf how much solute can dissolve in a solvent in a given temperature.
Saturated Solution- A solution in which the solute will no longer dissolve in the solvent. (ice tea - can't add any more sugar)
Unsaturated Solution- A solution in which you can still dissolve solute in.
Supersaturated solution- Is a solution that has more dissolved solute than is predicted by its solubility at its given temperature.
Acids- a substance that tastes sour, reacts with metals and carbonates, and turns blue litmus paper red or orange. (lemon, grapefruit- citric acid)
Corrosive- Eating away at other materials. (acids do this to metals)(can etch metals)
Indicator- A compound that changes color when in contact with and acid or a base. (litmus paper)
Base- A substance that tastes bitter, feel slippery, and turns red litmus paper blue. (ammonia, soaps, shampoos)(blue=base)
Hydrogen Ion- An atom of hydrogen that has lost its electron (key to reaction of acids)(hydrochloric acid)
Hydroxide Ion- a negative ion made of oxygen and hydrogen (bases dissolve in water
pH Scale- a range of values from 0-14 that expresses the concentration of hydrogen ions in a solution.
Neutralization- a reaction between an acid and a base.
Salt- any ionic compound that can be made from the neutralization of a base. (negative ion of acid + positive ion of base)
Digestion- The process that brakes down the complex molecules of foods.
Mechanical Digestion- a physical process in which large pieces of food are torn and ground into smaller pieces. (chewing)(size reduced but doesn't change composition)
Chemical Digestion- break large molecules down into small ones. (enzymes - speed up reactions)(mouth-saliva; ph=7 not sour or bitter - amylase enzyme)(stomach - very acidic - ph=2, helps break down, pepcin works best here)(small intestine ph=8, bi-carbonate ions; enzymes complete the breakdown of food)

Key Concepts
1-Understanding Solutions

  • A solution has the same properties throughout. It contains solute particles that are too small to see. (Tap water)(soft drinks)
  • A colloid contains larger particles than a solution. The particles are still too small to seen easily but are larger enough to scatter a light beam.
  • Unlike a solution, a suspension does not have the same properties throughout. It contains visible particles that are larger than the particles in solutions or collides. (pepper & water)
  • When a solution forms, particles of the solute leave each other and become surrounded by particles of the solvent.
  • Solutes lower the freezing point and raise the boiling point of a solvent. (salt - harder to form crystals - temp must drop lower to freeze) (liquids vs gas - molecules move different - solute makes it harder for molecules to move away - thus raising the bp)
2-Concentration and Solubility
  • To measure concentration, you compare the amount of solute to the amount of solvent or to the total amount of solution.
  • Solubility can be used to help identify a substance because it is a characteristic property of matter.
  • Factors that affect the solubility of a substance include: pressure (gases- soda, divers-benz), the type of solvent (oil & vinegar - polar compounds, paint - water vs oil based) and temperature (increase in temp increases solubility, making candy) (gases exception - less soluble at higher temps - hot soda).
3-Describing Acids and Bases
  • An acid is a substance that tastes sour, reacts with metals and carbonates and turns blue litmus paper red.
  • A base is a substance that states bitters, feels slippery and red litmus paper blue.
  • Acids and bases have many uses around the home and in industry.
4-Acids and Bases in Solution
  • An acid is any substance that produces hydrogen ions in water.
  • A base is any substance that produces hydroxide ions in water.
  • A low ph tells you that the concentration of hydrogen ions is high. In contrast, a high ph tells you that the concentration of hydrogen ions is low. low ph = acid; high ph = base
  • In a neutralization reaction, an acid reacts with a base to produce a salt and water
5-Digestion and ph
  • Foods must be broken down into simpler substances that your body can use for raw materials and energy.
  • Some digestive enzymes work at a low ph. For others, the ph must be high or neutral.