Properties of Matter: High School Chemistry

Chemistry  •  The  study  of  the  composi0on  and  transforma0on  of  

ma4er  •  Ma-er:  anything  that  has  mass  and  takes  up  space.  •  The  mass  of  an  object  is  a  measure  of  the  amount  of  

ma4er  it  contains  (kg)  •  The  volume  of  an  object  is  a  measure  of  the  space  

occupied  by  the  object  (Liters)  

Proper4es  useful  for  iden4fying  substances  •  Extensive  Property:  depends  

on  the  amount  of  ma4er  present  Ex:  -­‐volume  (L  or  cm3)              -­‐  mass  (g,  kg)    

•  Intensive  Property:  depends  on  iden4ty  of  substance  (not  amount)  Ex:  mel0ng  &  boiling  points,  density  (1.0g/cm3),  color,  odor,  luster,  duc0lity  (draw  into  a  wire),  conduc0vity  

Describing  Types  of  Ma-er  •  Ma4er  that  has  a  uniform  and  definite  composi0on  is  called  a  substance.  

–  Aluminum  (Al)  and  copper  (Cu)  are  examples  of  pure  substances    

•  Substances  can  be  classified  as  elements  or  compounds.  •  An  element  is  the  simplest  form  of  ma4er  that  has  a  unique  set  of  proper0es.  

– A  compound  is  a  substance  that  contains  two  or  more  elements  chemically  combined  in  a  fixed  propor0on.  

–   Ex.  Sucrose  (table  sugar)  C12H22O11  

Dis0nguishing  Substances  and  Mixtures  

With  your  cube…Record  in  Notes  •  Measure  the  proper0es  below  and  classify  them  as  extensive  or  intensive…  1.  Mass  in  grams  with  balance  (grams)  2.  Volume  in  cm3  with  ruler  (length  x  width  x  height)  3.  Density=  Mass  /  Volume  (amount  of  ma4er  in  a  space)  units:  grams/cm3  

4.  Color  5.    Luster  (is  it  shiny  or  dull?)  

Physical  Proper4es  of  Ma-er  •  Physical  Property:  a  characteris0c  that  can  be  observed  

or  measured  without  changing  the  substance’s  composi0on  

•  Examples:  – Hardness  – Texture  – Shape  – Flammability  – Density  – Conduc0vity  – Malleability  

Physical Properties of Some Substances Substance State Color Melting point (°C) Boiling point (°C)

Neon Gas Colorless –249 –246 Oxygen Gas Colorless –218 –183 Chlorine Gas Greenish-yellow –101 –34 Ethanol Liquid Colorless –117 78 Mercury Liquid Silvery-white –39 357 Bromine Liquid Reddish-brown –7 59 Water Liquid Colorless 0 100 Sulfur Solid Yellow 115 445 Sodium chloride Solid White 801 1413 Gold Solid Yellow 1064 2856 Copper Solid Reddish-yellow 1084 2562

This  table  lists  physical  proper0es  for  some  substances.  

•  The states of the substances are given at room temperature.

Physical  Changes  of  Ma-er    

•  Physical  Change:  a  change  in  a  substance  that  does  not  change  the  iden0ty  of  the  substance  –  Ex:  Phase  changes  (solid  à  liquid)    

Brainstorm  examples  of  reversible  vs.  non-­‐reversible  physical  changes…  

Chemical  Proper4es  &  Changes  •  Chemical  Property:  the  

ability  of  a  substance  to  react  with  or  transform  into  another  substance  

•  Chemical  Change:  substances  are  converted  into  other  substances  through  chemical  reac0ons  –  Bonds  are  broken  among  reactants,  and  new  bonds  form  among  products  (involved  ENERGY)  

Signs of a Chemical Change –  change in color or odor

–  formation of a gas

–  formation of a precipitate (solid)

–  change in light or heat (transfer of energy)

Biological  Example  of  Chemical  Reac4on:  Bombadier  Beetle  Defense  

•  Hydroquinone  +  oxygen  à  benzoquinone    •  (C6H4(OH)2)      +          O2                  à    (C6H4O2)  

Laws  of  Conserva4on  

•  Law  of  conserva4on  of  energy:  energy  is  not  created  or  destroyed,  but  only  changes  form  –  Fireworks  (chemical  à  light  and  energy)  

•  Law  of  conserva4on  of  mass:  in  any  physical  change  or  chemical  reac0on,  mass  is  conserved.    

Dis0nguishing  Substances  and  Mixtures