Chemistry- Unit 1

Unit 1.1

Household Product Safety(HHPS)

Types of frames used around the symbols are

  • Inverted Triangle- It means that the container is dangerous
  • Octagon- It means the product inside the container is dangerous

Workplace Hazardous Materials Information System (WHMIS)

PictogramsNameThe danger
Exploding BombExplosives, Self- reactives, Organic Peroxides
CorrosionSkin corrosion/burns, Eye damage, Corrosive to metals
Flame Over CircleOxidizing gases, liquids and solids
Gas CylinderGases under pressure
EnviromentAquantic toxicity
Skull & CrossbonesAcute toxicity(fatal or toxic)
Exclamation MarkIrritant(eye & skin), Skin sensitizer, Acute toxicity,Narcotic effects, Respiratory tract irritant, Hazardous to ozone layer(non-mandatory).
Health HazardCarcinogen, Mutagenicity, Reproductive toxicity, Respiratory sensitizer, Target organ toxicity, Aspiration toxicity.
FlameFlamemables,Pyrophorics,Self-heating, Emits-flammable gas, Self reactives, Organic peroxides.

Material Safety Data Sheet (MSDS) identifies the ==specific== chemical and physical hazards associated with the product.


Properties and Classification of Matter

Properties: describe the physical appearance and composition of a substance

==Physical== Properties include:

  • Boiling or condensation point
  • Melting or freezing point
  • Malleability(capable of being altered or controlled by outside forces or influences.)
  • Ductility(the ability of a material to be drawn or plastically deformed without fracture)
  • Color, state, and solubility
  • Crystal formation
  • Electrical conductivity and magnetism

==Chemical== Properties describe how reactive a substance is

Chemical properties include:

  • Ability to burn and flash point
  • Behavior in air
  • Reactions with water, acids, heat and litmus

Pure Substances and Mixtures

  • Pure substances- All substances that make up the substance are identical, so its chemical and physical are constant. (element of compound)
    • Element- Pure substance that @@cannot@@ be broken down into an other substances
    • Compound- chemical combination of two or more elements in a specific ratio.
  • Mixtures- Combination of two or more pure substances
  • Hetereogenous Mixtures (different):
    • Mechanical Mixtures- different substances are visible
    • Suspentions- Where componets are in different states
    • Colloids- Suspended substances cannot be easily seperated
  • Homogenous mixture(same throughout):
    • Solutions- seperate compounds are not visible;one substance is dissolved in another.

Chemical Reactions

Two important features of a chemical reaction are:

  1. New substances with new physical and chemical properties are formed
  2. Energy flows into or out of the system during a reaction.

To indicate a chemical change 2 or more of the following should occur:

  • Heat or light is produced or absorbed
  • the starting material is used up, or a new substance is produced
  • There is a change in color
  • A percipitate( solid) or bubbles(gas) formed in the liquid
  • The change is difficult to reverse
  • New odour forms

Atomic Models

  1. Greek Theory- Proposed that matter could be composed of small, indivisble particles

  2. John Dalton (Billiard Ball Theory)-

    • He rediscovered the atomic concept of matter
    • States the law of multiple proportions
    • When 2 or more elements form a series of Compounds form a fixed mass that have interger ratios of each other
    • Ex. Methane:CH4, has a 1:4 ratio of carbon:hydrogen
    • To behave in this manner atoms need to be formed
  3. JJ Thompson (Plum Pudding or Raising Bun Model)-

    • Most famous for discovering the electron
    • Thompson worked with a Cathode Ray Tubes(CRTs) .
    • Cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons.
    • Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup."

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  4. Rutherford (Planetary model)-

    • Rutherford fixed the problem in Thompson’s model
    • Rutherford designed an eperiment that helped fix the problem called the scattering experiment.
    • Alpha particles were expected to pass through the thin gold foil with little scattering.
    • Rutherford assumed that the alphas were interacting electrositcally with solid centers of the atom.
    • He discovered the nucleus with protons and neutrons.
  5. Niels Bohr (Bohr Model)-

    • Bohr modified Rutherfors’s theory
    • He observed that electrons don’t orbit the nucleus but they exist with diffrent energy levels.
  6. Schroedinger ( Electron Cloud or Quantum Mechanical Model)-

    • An elvolving model but currently thought of as a cloud of negative charges.

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