Hi everyone,
Could someone direct me somewhere that breaks down the DAT, what supplies to prepare with, etc ? I have 0 knowledge about this exam and would appreciate any help to guide me to a good starting point.
General Chemistry: Be familiar with periodic trends and the locations of the alkali metals, alkaline earth metals, halogens, noble gases, transition metals, and lanthanides/actinides, as well as the definitions of atomic number, mass number, atomic weight, and how to classify (metallic, ionic, molecular, and covalent network) and name ionic and molecular compounds. Also, know the common classes of general reactions and their properties (e.g., single displacement reactions are all redox reactions, while all double-displacement reactions aren't redox).
Know how to balance equations and determine empirical formulas if given the percentages of element in a compound, as well as how to calculate theoretical yield and determine limiting reagents. Also, know that a solution is comprised of one or more solutes and a single solvent, and how to express solute concentration (molarity, molality, and osmolarity/osmolality), and how to correctly answer dilution problems (Note: it's not always as simple as M1V1 = M2V2!). Also, know which species tend to be soluble (all strong acids/bases, AI elements, nitrates, acetates, and most sulfates), as well as which species aren't soluble (most phosphates, sulfides, hydroxides, and etc.).
You should thoroughly review thermochemistry, and be familiar with the three laws of thermodynamics (their definitions and implications), as well as enthalpy, entropy, and Gibbs free energy. Also, know that the aforementioned three functions are state functions, while q (heat) and w (work) are not state functions. Also, be familiar with what a formation reaction is (it produces one mole of a product from the elemental states of elements which comprise it), as well as Hess's law and calculating enthalpy from enthalpies of formation. Lastly, know which phase-changes are endothermic/exothermic and how to use the equation q = mCT to calculate the heat transfer associated with phase changes (note: enthalpy, H, is only equal to heat, q, at constant pressure).
Know how to determine electronic configurations as well as the exceptions (Mo, Cr, Ag, Au, and Cu) to the building up principle (completely half-filled or fully-filled orbitals of a particular shell have increased stability). Know the names of the quantum numbers, the letters which designate them, and what they mean (e.g., n = shell number, l = orbital type, ml designates which orbital, and ms designates spin), and the shapes of, at least, the s, p, and d orbitals (the f orbital is probably too complex for the DAT), and know the Bohr Model of the Atom and the gist of the Heisenberg Uncertainty Principle. Also, know that shorter single bonds are associated with greater stability and strength.
Learn the trends concerning atomic and ionic radius, as well as electron affinity and electronegativity for the periodic table, and what differentiates them, and how to compare different species on any one of them (e.g., fluorine is the most electronegative element on the periodic table, followed by oxygen, followed by chlorine, and so forth), as well as how to determine Lewis structures and whether a species is polar, and how to distinguish its molecular and electron domain geometry. Also, learn how to determine how many sigma and pi bonds are present in a molecule.
For gases, be aware of the equation P1V1/(nT1) = P2V2/(nT2), as well as the ideal gas law, PV = nRT, and PMw = dRT, and when to use R = 0.0821 or R = 8.314. Know which conditions favor the ideal gas assumptions (high temperature and low pressure), and what they are (molecular volume is negligible, no intermolecular interactions, the average kinetic energy of the molecules is directly proportional to temperature, and et cetera). Also, be familiar with the units for pressure (1 atm = 1 Bar = 760 mmHG = 760 torr = 101,325 Pa), and STP as well as standard conditions. Know that lighter molecules effuse faster than heavier molecules by a factor proportional to the square root of the quotient of their molar masses, i.e., sqrt(heavy molecule molar mass/light molecule molar mass), and Dalton's law of partial pressures, and that 1 mole of gas at STP takes up 22.4 liters of volume.
Also be familiar with colligative properties (freezing point depression, -iKm and boiling point elevation, iKm, and that we use molality, m, instead of molarity, M, here). Be familiar with phase diagrams and how to identify the triple point, critical point, normal melting and boiling point, where a supercritical fluid lies and its definition, as well as where the boundary for the liquid-solid and liquid-gas lines lie, and whether a compound can undergo sublimation or deposition.
Be familiar with how to determine the rate law for a reaction if given experimental values of changes in its rate, and how to determine the units of a rate constant, as well as the characteristics that define zero-order, 1st order, and 2nd order rate laws (e.g., 1st order reactions have a half-life irrespective of sample size, i.e, t1/2 = 0.693/k, and know how to determine how much of a compound remains if given its half-life and the knowledge that it's 1st order). Know also how catalysts affect reaction (they stabilize the transition state, thereby lowering the activation energy via providing an alternative mechanism), as well as the mandates for a reaction to occur (a collision with sufficient energy must occur in the proper orientation, and how temperature affects this). Know also how temperature and catalysts affect the rate law constant and the like.
Know how to calculate equilibrium and which species are included in the calculation (only gases and aqueous species), and Keq, Kw, Ka, Kb, and Ksp. Also know that pH = -log[H+], and that pH + pOH = 14, and pKa + pKb = 14, and [Ka][Kb] = 1 x 10^(-14). Know also how to calculate the acidity of a solution if given its molar concentration and its Keq, and how to distinguish between buffers and titrations, and the characteristics that define each (buffers can be made with a strong species, but the actual buffer cannot contain any strong species, while at least 1 strong species must be present in titrations, and the purpose of both). Also know the Henderson-Hasselbach equation and how to understand titration curves.
Know the definitions of alpha decay, beta decay, electron capture, and positron emission, and which characteristics define stable species (e.g., a N/Z ratio of 1 for species up to calcium, and that species for Z > 83 are all radioactive), and how to determine elements that result from decay. Know also what nuclear binding energy is, and that Fe56 is the most stable nucleus in the world (it has the highest nuclear binding energy per nucleon of any known element).
Finally, understand the difference between galvanic (voltaic) and electrolytic cells (the former are spontaneous, i.e., have Ecell >0, while the latter have Ecell <0 and are nonspontaneous), and that oxidation occurs at the anode while reduction occurs at the cathode, and which ions migrate where. Know also that unlike H, S, and G, Ecell does not multiply with moles, and know how to work with redox potentials if asked to compute an answer involving redox reactions. Know also how to assign oxidation states to species, and how to balance redox reactions.
Organic Chemistry: Be familiar with the reactions for alkanes, alkenes, alkynes, alcohols, benzenes, amines, radicals, organometallics, carbonyl compounds (including aldehydes, ketones, and carboxylic acids and their derivatives), and especially alpha carbon reactions (e.g., the Wittig Reaction, Claisen Condensation, Aldol Condensation, and so forth). Malonic ester and acetoacetic ester synthesis are important reactions as well. Also, be familiar with the characteristics of and how to distinguish SN1/SN2/E1/E2 reactions. (E.g., substitution reactions are associated with nucleophiles, while elimination reactions are associated with bases, strong species are associated with SN2/E2, while a SN1/E1 reactions form a racemic mixture when they occur, and down the line).
Also, have a firm understanding of the principles of aromaticity and resonance, the stability of carbocations, radicals, and carboanions, and molecular and hybridized orbitals, as well as predicting the strengths of acids and bases, and determining which proton on a molecule is the most acidic. I would also recommend memorizing the pKa values for the generic classes of organic compounds (e.g., carboxylic acids have pKas of approximately 5, while ketones have pKas of about 19, with aldehydes somewhat lower, alcohols and water have pKas of approximately 15, amines 36, and so forth).
Make sure you can assign the correct structure to a molecule if given its C13 NMR spectrum. Often times these molecules tend to have similar functional groups, but differ in their connectivity, so it's not enough to merely know that, for example, carbonyl carbon signals appear in excess of ppm 160. Needless to say you will need to have an understanding of stereochemistry and determining whether a configuration is R or S, and know that the only way we can determine whether a compound will rotate light left or right is by placing it in a polarimeter (and that if one rotates left, then the other must rotate right, but we cannot determine beforehand whether R or S will rotate left or right).
Be familiar with the various laboratory techniques and how they're used to separate and classify compounds or elucidate chemical structure (e.g., extractions, chromatography, melting points, and et cetera).
Proteins, nucleic acids, and lipids may also appear on the exam, and Chad's Videos as well as KBB covers these topics.
Note that not all of these topics will appear on your exam, but any of them may very well so. Undoubtedly, that means that you will study for things you will not encounter on the actual exam, but it is the only way you can be certain that you will be prepared for the majority of what will show up on the test.
