CHEM 16 APE PART 1

• Chemistry


  The study of matter, which is commonly defined as anything that has mass, rest mass, or space and has volume, space, or mass
• What chemistry studies


  • Matter and its composition
  • The changes of matter
  • The properties of substances
  • NOT the interaction of living systems (branches of BIOLOGY)
• States of matter


  • Solid: Particles close together and organized
  • Liquid: Particles close together but not held rigidly in position
  • Gas: Particles far apart and disorganized
• Kinetic molecular theory


  All matter consists of extremely minute particles (atoms, molecules, or ions) that are in constant motion<|>There are forces of attraction between particles that allow them to form structures or move past one another<|>There are net forces of attraction between particles in all states – generally small forces in gases and large forces in liquids and solids<|>The forces between particles have a significant role in determining the properties of matter<|>As a rule, increasing temperature corresponds to faster motions of atoms and molecules
• Physical property


  Can be observed without a chemical reaction
• Chemical property


  Describes the potential of a substance to undergo a chemical change or reaction by virtue of its composition
• Physical properties


  • Color
  • State of matter
  • Melting point
  • Boiling point
  • Density
  • Viscosity
  • Electrical Conductivity
• Chemical properties


  • Flammability
  • Heat of Combustion
  • Toxicity
  • Radioactivity
  • Chemical Stability
  • Half-life
  • Flammability
  • Corrosiveness
• Intensive property


  Independent on the amount of substance being measured
• Extensive property


  Dependent on the amount of substance being measured
• Examples of intensive properties


  • Boiling Point
  • Melting Point
  • Freezing Point
  • Density
  • Hardness
  • Luster
  • Temperature
• Examples of extensive properties

  • Mass
  • Volume
  • Length, Height, Width
  • Weight
• Physical change


  Changes in the physical properties of a substance<|>The identity of a substance is preserved even though it may have changed its physical state or the size, shape, mass, or volume of the substance itself<|>Does not form a new substance by virtue of its chemical composition<|>Substance is still composed of the same particles before and after the change
• Chemical change


  2+ substances (reactants) are transformed into one or more completely different substances (products)<|>A chemical equation is used to represent chemical change
• Examples of chemical changes

  • Digestion of food
  • Heating sugar to form caramel
  • Neutralization reaction of HCl and NaOH
  • Rusting of iron
• Examples of physical changes


  • Pouring melted gold pieces into a mold
  • Sublimation of dry ice into carbon dioxide vapor
  • Turning pieces of wood into a wooden table
• Element


  Pure substances that are composed of only one type of atom
• Compound


  Substances that are composed of two or more different elements held together by chemical bonds<|>These substances are referred to as chemical compounds<|>A compound has distinctly different characteristics from its parent elements, and it has a definite percent composition (by mass) of its combining elements<|>Some compounds are composed of ions, which are electrically charged atoms or group of atoms<|>Some compounds are composed of molecules, which are the smallest discrete units that retain the composition and chemical characteristics of the compound<|>Composition of any compound is represented by its chemical formula
• Homogeneous mixture


  Consist of two or more substances in the same phase<|>Often called as solutions, these mixtures consist of two components: solute and solvent
• Heterogeneous mixture


  Type of mixture that do not have uniform composition<|>The uneven texture of the material can be often detected by the naked eye
• Solute


  The component that is present in lesser amount
• Solvent


  The component that is present in larger amount and dissolves the solute
• Soluble


  When a solid solute completely dissolves in a solvent
• Insoluble


  When the solid solute does not dissolve in a solvent
• Miscible liquids


  Two liquids that completely dissolve in each other
• Immiscible liquids


  Two liquids that are not miscible and form layers
• Colloid


  A type of heterogeneous mixture that has a homogeneous façade<|>In a colloidal system, one substance is dispersed evenly throughout another<|>The particles are only suspended in the mixture<|>It consists of two separate phases: a dispersed phase and a dispersing medium
• Types of colloids


  • Aerosols
  • Foams
  • Emulsions
  • Sols
  • Gels
• Properties of colloids


  • Tyndall Effect
  • Brownian Movement
  • Electrical Properties
  • Stability and Unstability
  • Adsorptive Property
• Decantation


  A process that separates components of a mixture based on differences in density<|>Involves sedimentation and decanting
• Filtration


  A process utilized to separate solids from liquids or gases using a filter medium that enables the fluid to pass through however not the solid
• Evaporation


  Can be used as a separation method to separate components of a mixture with a dissolved solid in a liquid<|>The liquid is evaporated, meaning it is converted from its liquid state to gaseous state
• Distillation


  The process of separating the components or substances from a liquid mixture by using selective boiling and condensation<|>Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids)
• Sublimation


  The separation technique where a substance makes a transition from the solid to the gas state directly, without going through the liquid stage
• Other methods of separation

  • Magnetic separation
  • Sieving
  • Crystallisation
  • Chromatography
• Measurement


  A quantitative description of any physical quantities in studying chemistry and is composed of numbers and units<|>Conversion factors are needed to convert from one unit of measurement to another
• SI units


  The International System of Units
• Seven SI base units

  • Length (meter)
  • Mass (kilogram)
  • Time (second)
  • Electric current (ampere)
  • Thermodynamic temperature (kelvin)
  • Amount of substance (mole)
  • Luminous intensity (candela)
• Selected prefixes used in the metric system

  • Kilo (k)
  • Hecto (h)
  • Deca (da)
  • Deci (d)
  • Centi (c)
  • Milli (m)
  • Micro (μ)
  • Nano (n)
  • Pico (p)
• Temperature scales


  Celsius (°C)<|>Fahrenheit (°F)<|>Kelvin (K)