There are two topics in Unit 2 which at first seem unrelated but do share some common principles, so it makes sense to study them together.
Chemical kinetics (our first topic in Unit 2) is the study of the rate of chemical reactions, why the rates are fast or slow, and what other information these reaction rates can give us.
The second topic of Unit 2 is nuclear chemistry, which is (as it sounds) that area of chemistry governed by changes within the nuclei of atoms. This topic will shed light on areas you may be familiar with (or at least have heard of) from outside of class, like radioactivity, nuclear power, and nuclear weaponry.
Unit 2 Learning Objectives
Chemical Kinetics
- Manipulate any mathematical equation involving logarithms.
- Define or explain and apply the definition for the following terms: reaction rate, average and instantaneous rates, rate constant, reaction order, rate law, half-life, activated complex, activation energy, mechanism, elementary reactions (elementary steps), molecularity, rate determining step, catalyst (homogeneous and heterogeneous)
- Distinguish among the average, instantaneous and initial rates for a chemical reaction.
- Explain the effect of the physical state of the reactants, frequency, kinetic energy (temperature), catalyst, and orientation of collisions on the reaction rate.
- Express the rate of a reaction in terms of the change in concentration of all reactants and products given the balanced chemical equation for the reaction.
- Calculate the rate of formation or consumption for a reactant or product in a chemical reaction given the rate of formation or consumption any other reactant or product in the reaction.
- Determine the order of a reaction, rate law and calculate the rate constant k (and the units of k) for a reaction from a series of experiments given the measured initial rates for various concentrations of reactants.
- Using the integrated rate law equation for first order reactions only, calculate the rate constant, half-life, time or percent of starting material given any two of the variables.
- Determine whether a rate law for a reaction of form A → products is zero, 1st, or 2ndorder given concentration vs. time data. Know what graphs can be used to make this determination, and what quantities are represented but the slope of the resulting line.
- Determine the rate constant from the slope and the concentration at a given time from the integrated rate law equation resulting from the plot of first-order data.
- Summarize the two types of rate laws and the methods by which they can be determined.
- Write the rate law for elementary reactions/steps.
- Discuss the relationship between the reaction mechanism and the rate law.
- Determine the molecularity of each elementary reaction, rate determining step and the overall balanced equation given the mechanism for a reaction.
- Given the mechanism for a reaction write the rate law.
- Given a mechanism in which the rate determining step is not the first step, write the rate law.
- Describe the collision model for chemical reactions.
- Draw reaction profile diagrams and identify reactants, products, the activated complex, Eactand ΔE.
- Describe the effect of a catalyst on the energy profile diagram of a reaction.
- Explain how a catalyst works and how it fits into the collision model for chemical reactions.
- Identify the catalyst and the intermediate given the mechanism for a reaction.
- Explain the temperature dependence of reaction rates.
- Define and calculate Eact, the Arrhenius constant or frequency factor (A), rate constant (k), or temperature for a chemical reaction.
- Using two sets of temperature and rate constants, calculate any of the following variables: the activation energy, the temperature, or rate constant
Nuclear Chemistry
- Define and apply the definition for radioactive decay.
- Classify the types of radioactive decay processes and describe the characteristic of each.
- Write the nuclear symbol for protons, neutrons, electrons, alpha particles,
beta particles and positrons. - Write balanced nuclear equations for radioactive decay processes or nuclear transmutations.
- Complete and balance nuclear reactions given all but one of the particles involved.
- Describe the role that the neutron-to-proton ratio, magic numbers, and odd-even number (protons & neutrons) play in accounting for the stability of a nucleus.
- Predict whether a nuclide is likely to be stable or unstable (radioactive). If unstable, predict the most likely mode of decay to achieve stability. (For example, explain why tritium, 3H, is unstable.)
- Calculate the half-life of a radioactive nuclide given the rate constant or vice-versa.
- Given any two of the following variables involved in the rate of radioactive decay, calculate the third. Variables: 1) Amount of sample, 2) Activity, 3) Decay constant, 4) Half-life, 5) Time.
- State the basic assumptions made when using radiometric dating to determine the age of objects.
- Calculate and predict the potential age of an object based on levels of concentration or C-14 within that sample or based on the given isotope ratio.
- Describe how radioactivity of radioactive substances is detected using a badge dosimeter, Geiger counter, and scintillation counter, radiotracers.
- Calculate the energy or mass change in a nuclear reaction, given one of these quantities.
- Calculate the mass defect, total nuclear binding energy, and binding energy per nucleon for a nuclide given its nuclear or atomic mass and the masses for protons, electrons and neutrons.
- Distinguish between fission and fusion and state what type of nuclei will undergo these processes.
- Based on the plot of binding energy/nucleon versus mass number, predict whether isotopes would react via fusion or fission reactions.
- Identify and balance nuclear equations for fission and fusion reactions.
- Briefly describe the general design of a nuclear reactor.
- State the purpose of the fuel rods, control rods, moderator and cooling fluid in nuclear reactors.
- Identify the advantages of a fusion reactor over a fission reactor and explain the problems with using nuclear reactors as energy sources.
Unit 2 Topics
Study these in order:
