Chemistry

• An acid is a substance that donates hydrogen ions (H ) in a chemical reaction.
• Acids form acidic solutions in water.
• Acids are sources of hydrogen ions, H+.
• Hydrochloric acid produces hydrogen ions: HCl(aq) → H+(aq) + Cl-(aq).
• Acidic solutions have pH values less than 7.
• Alkalis form alkaline solutions in water.
• Alkalis are sources of hydroxide ions, OH-.
• Sodium hydroxide produces hydroxide ions: NaOH(aq) → Na+(aq) + OH-(aq).
• Alkaline solutions have pH values greater than 7.
• A neutral solution is neither acidic nor alkaline.
• A neutral solution has a pH value of 7.
• Acid-alkali indicators can show whether a solution is acidic, neutral (pH 7) or alkaline.
• A soluble salt can be prepared by reacting an acid with a suitable insoluble reactant including a metal, a metal oxide, or a carbonate.
• The name of a salt has two parts: the first part comes from the metal, metal oxide or metal carbonate, and the second part comes from the acid.
• Hydrochloric acid produces chloride salts.
• Nitric acid produces nitrate salts.
• Sulfuric acid produces sulfate salts.
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• Solids


  Particles in fixed arrangements, vibrate around fixed positions, have little kinetic energy, strong forces between them
• Liquids


  Particles slightly more widely spaced, not touching as much, have intermediate forces between them, vibrate more, no fixed positions
• Gases


  Particles further apart, have large amounts of kinetic energy, not held in fixed positions, weak forces between them
• Conversions between states of matter

  1. Melting (solid to liquid)

  2. Freezing (liquid to solid)

  3. Boiling/Evaporating (liquid to gas)

  4. Condensation (gas to liquid)
• Particles with the most kinetic energy evaporate first, leaving remaining particles with lower average kinetic energy
• In a closed container, condensation and evaporation occur simultaneously
• Diffusion


  Net movement of particles from an area of high concentration to an area of low concentration, down the concentration gradient, no energy required, a passive process
• Diffusion example


  • Ammonia and hydrochloric acid in a glass tube, forming ammonium chloride ring
• Solute


  Solid which dissolves in a solvent
• Solvent


  Liquid in which the solute dissolves
• Solution


  Mixture of the solvent and solute
• Saturated solution


  Solution where no more solute can be dissolved in the solvent
• Atom


  Smallest particle of a substance that can exist
• Element


  Contains only one type of atom, cannot be split by chemical means
• Compound


  Two or more elements chemically combined, cannot be separated back into constituent elements
• Mixture


  Contains two or more elements not chemically combined, can be separated into constituent components
• Pure substance


  Contains only one type of material, has a fixed boiling point
• Filtration


  Separates an insoluble solute from a solvent
• Evaporation


  Separates a soluble solute from a solvent
• Separating immiscible liquids


  Using a separating funnel