Chemical composition

• Compound

  2 or more substances chemically bonded together
• Pure substance

  Single substance not mixed with anything else
• Impure substance

  A Mixture
• Element

  • Simplest pure substance
  • basic building blocks of living things+ non-living matter
  • cannot be broken down into simpler substances by chemical means
• Mixture 


  2 or more substances physically mixed together
• mixture ( characteristic)

  • show characteristics of constituent
  • elements/ compounds retain their properties
  • separated by physical methods
• Compound( characteristic)

  • fixed no. Of atoms of diff elements
  • made up of molecules/ ions
  • constitute elements present in fixed proportions
  • diff properties of constitute elements
  • separated by chemical methods
• homogeneous mixtures

  Particles of each component distributed uniformly
• Heterogeneous mixtures

  Particles of each component not distributed uniformly
• Suspension

  • Heterogeneous mixture
  • substances do not dissolve, diff parts will separate
  • insoluble particles will settle to the bottom when left to stand for some Time.
  • particles bigger
  • not clear heterogeneous mixture
• Solutions

  • homogeneous mixture of 2+ substances
  • solute( dissolves in substance) dissolves into a solvent( dissolves substance) fully and they stay mixed together
  • smaller particles
  • clear homogeneous mixture
  • particles can pass through filter paper
• Solubility 


  Max mass solute can dissolve in fixed volume of solvent at a certain temp.
• Affect solubility

  • Type of solute
  • type of solvent
  • temperature
• Dilute solution


  Small amt of solute in large amt of solvent
• Saturated solution


  Greatest amt of solute that can dissolve in a fixed Amy of solvent at a given temp.
• Concentrated solution


  Large amt of solute and small amt of solvent
• Rate of dissolving

  • Temp( higher temp - higher rate)
  • Size of solute particles ( smaller size - higher rate)
  • rate of stirring ( high term rate if stirring - higher rate of dissolving)