The object of reflection for this journal is your experience in learning the material during the week. You are required to make one entry per week, each You are advised to make entries regularly rather than completing it right before a submission date, and the quality of reflection should be the emphasis of your entries rather than over-emphasis on the word count.
Chapter 7 Overview and Learning Objectives
OVERVIEW
Molecules are three-dimensional--they have a shape--and many of the properties of compounds are determined by this three dimensional shape. The shapes of molecules are determined by the steric repulsion of electron groups (lone pairs and chemical bonds) around a central atom. Five main categories result: linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral. If some of the electron groups attached are lone pairs of electrons, there are additional groups--bent, trigonal pyramidal, see-saw, T-shaped, linear, square pyramidal, and square planar. If these shapes are asymmetrical and have polar bonds in the molecule, the whole molecule can be polar. Intermolecular forces are attractions between molecules that come about because of polar bonds and molecules. In this chapter we also discuss orbital hybridization, which seeks to connect the idea of molecular shape with the previous discussion of atomic orbitals.
Chapter 8 Overview and Learning Objectives
OVERVIEW
Chemical reactions are the transformation of substances into other substances by the rearrangement of atoms in the molecules of the reactants to form product molecules. Chemical reactions are described using chemical equations. Balanced equations reflect the Law of Conservation of Matter, where in a chemical reaction, the number and types of atoms must be the same on both sides of the equation. The coefficients in a balanced chemical reaction tell us how many molecules (or moles) of each reactant combine to form how many molecules (or moles) of each product. The mole ratio based on the coefficients in the balanced chemical equation can be used as a conversion factor to calculate how much of one substance in a reaction compares to how much of another substance is needed or is produced. These are known as stoichiometry calculations and involve grams to moles (using the molar mass), moles to moles (using the mole ratios from the balanced chemical equation), and moles to grams (using the molar mass). These kinds of calculations are simply multistep conversion factor/dimensional analysis problems. Limiting reactant problems are a type of this calculation where the mass (or number of moles) about each reactant is given and you determine which is present in excess (or limiting) amounts. The limiting reactant determines how much product is produced. A stoichiometry calculation gives the theoretical yield. The actual yield is the amount product obtained by actually running the reaction. Percent yield is the actual yield/theoretical yield x 100%. Since combustion reactions (a fuel + molecular oxygen yields carbon dioxide and water) are a prominent example of chemical reactions in this chapter, there is also a discussion of the increase in CO2 concentrations in the atmosphere due to the burning of fossil fuels (coal, oil/gasoline/diesel/jet fuel, and natural gas). CO2 is a greenhouse gas that warms the atmosphere and planet due to its absorption of IR radiation.
Write an academic reflection in four paragraphs: describe, interpret, evaluate, and plan.
What did you learn this week?
What activities helped you to learn?
What activities did you find engaging?
How will you do to better understand your muddy points for the week?