Chemistry

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Solutions

Standards of Focus

  • A solution is a homogeneous mixture of a solute dissolved in a solvent.
  • Properties of solutions can be explained in terms of chemical bonds and intermolecular forces.
  • The solubility of a solute in a given amount of solvent is dependent on the temperature, the pressure, and the chemical natures of the solute and solvent.
  • The concentration of a solution may be expressed as: molarity (M), percent by volume, percent by mass, or parts per million

    Acids and Bases

    Standards of Focus

    • Behavior of many acids and bases can be explained by the Arrhenius theory. Arrhenius acids yield H+ (aq), hydrogen ion. Arrhenius bases yield OH- (aq).
    • Indicators can change color based on pH
    • In the process of neutralization, an Arrhenius acid and an Arrhenius base react to form a salt and water.
    • Titration is a laboratory process in which a volume of solution of known concentration is used to determine the concentration of another solution
    • The acidity or alkalinity of a solution can be measured by its pH value. The relative level of acidity or alkalinity of a solution can be shown by using indicators.
    • On the pH scale, each decrease of one unit of pH represents a tenfold increase in hydronium ion concentration

    Kinetics and Equilibrium

    Standards of Focus

    • Collision theory states that a reaction is most likely to occur if reactant particles collide with the proper energy and orientation.
    • The rate of a chemical reaction depends on several factors: temperature, concentration, nature of reactants, surface area, and the presence of a catalyst.
    • Some chemical and physical changes can reach equilibrium.
    • At equilibrium the rate of the forward reaction equals the rate of the reverse reaction. The measurable quantities of reactants and products remain constant at equilibrium.
    • Le Chatelier’s principle can be used to predict the effect of stress (change in pressure, volume, concentration, and temperature) on a system at equilibrium.
    • Energy released or absorbed by a chemical reaction can be represented by a potential energy diagram.
    • Energy released or absorbed by a chemical reaction (heat of reaction) is equal to the difference between the potential energy of the products and the potential energy of the reactants.
    • A catalyst provides an alternate reaction pathway which has a lower activation energy than an uncatalyzed reaction.
    • Entropy is a measure of the randomness or disorder of a system. A system with greater disorder has greater entropy.
    • Systems in nature tend to undergo changes toward lower energy and higher entropy.

    Nuclear Chemistry

    Standards of Focus

    • Nuclear reactions can be represented by equations that include symbols which represent atomic nuclei (with the mass number and atomic number), subatomic particles (with mass number and charge), and/or emissions such as gamma radiation.
    • Stability of isotopes is based on the ratio of the neutrons and protons in its nucleus. Although most nuclei are stable, some are unstable and spontaneously decay emitting radiation.
    • A change in the nucleus of an atom that converts it from one element to another is called transmutation. This can occur naturally or can be induced by the bombardment of the nucleus by high-energy particles.
    • Determine decay mode and write nuclear equations showing alpha and beta decay
    • Spontaneous decay can involve the release of alpha particles, beta particles, positrons, and/or gamma radiation from the nucleus of an unstable isotope.
    • These emissions differ in mass, charge, ionizing power, and penetrating power.
      Nuclear reactions include natural and artificial transmutation, fission, and fusion. There are benefits and risks associated with fission and fusion reactions.
    • Compare and contrast fission and fusion reactions
    • Energy released in a nuclear reaction (fission or fusion) comes from the fractional amount of mass converted into energy. Nuclear changes convert matter into energy.
    • Energy released during nuclear reactions is much greater than the energy released during chemical reactions.
    • There are inherent risks associated with radioactivity and the use of radioactive isotopes. Risks can include biological exposure, long-term storage and disposal, and nuclear accidents.
    • Radioactive isotopes have many beneficial uses. Radioactive isotopes are used in medicine and industrial chemistry, e.g., radioactive dating, tracing chemical and biological processes, industrial measurement, nuclear power, and detection and treatment of diseases.

    Organic Chemistry

    Standards of Focus

    • Organic compounds contain carbon atoms which bond to one another in chains, rings, and networks to form a variety of structures.
    • Saturated hydrocarbons contain only single carbon-carbon bonds.
    • Unsaturated hydrocarbons contain at least one multiple carbon-carbon bond.
    • Functional groups impart distinctive physical and chemical properties to organic compounds.
    • Isomers of organic compounds have the same molecular formula but different structures and properties.
    • Types of organic reactions include: addition, substitution, esterification and combustion.

    Redox

    Standards of Focus

    • An oxidation-reduction (redox) reaction involves the transfer of electrons (e-).
      Oxidation is losing e-, reducing is gaining e-
    • Oxidation numbers (states) can be assigned to atoms and ions. Changes in oxidation numbers indicate that oxidation and reduction have occurred.
    • An electrochemical cell can be either voltaic or electrolytic. In an electrochemical cell, oxidation occurs at the anode and reduction at the cathode.
    • A voltaic cell spontaneously converts chemical energy to electrical energy.
    • An electrolytic cell requires electrical energy to produce chemical change. This process is known as electrolysis.