# Shared Flashcard Set

## Details

Chemistry 132 Midterm
Definitions, Equations, Etc
53
Chemistry
10/12/2014

Term
 kinetics
Definition
 refers to the rate at which a chemical reaction occurs (reaction rate)
Term
 reaction rate
Definition
 the change in concentration of a reactant of product over time
Term
 rate law
Definition
 the math expression relating the reaction rate to the rate constant and the reaction constant
Term
 reaction orders
Definition
 x & yare partial reactions that state the control on the rate of the reaction by each of the reactants individually
Term
 the overall reaction =
Definition
 the sum of all the powers of all the partial reactions
Term
 reasons for different reactions
Definition
 0^0 = a catalyst, thus independent of [reactant]1^0 = increase collision rate which is dependent of [reactant]2^0 = a) increase in collision rate b) more effective collisions c) a lower activation energy d) often exothermic so an even lower activation energy
Term
 isolation method
Definition
 how to determine the rate law by measuring the dependency of the reaction rate to the concentration of each reactant
Term
 Savante Arrhenius described
Definition
 quantitatively the collision theory
Term
 Arrhenius Equation #1
Definition
 k = Ae^(-Ea/RT)
Term
 Arrhenius Equation #2
Definition
 derived by taking the natural log of equation #1ln (k) = ln (A-Ea/RT)
Term
 Arrhenius Equation #3
Definition
 determining Ea from two different T's and k'sln (k1) = ln (A-Ea/RT1)ln (k2) = ln (A-Ea/RT2) ln (k1-k2) = Ea/R (ln( A-1/T1) - (ln(A - 1/T2))Subtract these two and eliminate Aln (k2/k1) = -Ea/R ((1/T2 - 1/T1))
Term
Definition
 1) may occur slowly or rapidly2) only products are formed3) reactant disappear to the point of LR4) con use stoichiometry of balanced chemical equation to find the moles of the product
Term
Definition
 1) may occur slowly or rapidly2) both products and reactants produced3) stoichiometry not useful in finding moles 4) Equilibrium (keq)5) ratio of reactants to products is useful in finding moles
Term
 Equilibrium
Definition
 dynamic state where two processes are occurring at the same time in a system until no farther net change occurs
Term
 how to find moles in aequilibrium reaction
Definition
 though stoichiometry is not useful, there is a relationship that there must be less of the initial reactants than products, thus a ratio of reactants to products is useful
Term
 equilibrium constant (k)
Definition
 a quantitative expression of the distribution of reactants vs products for a system at equilibrium
Term
 k = 1
Definition
 a 50:50 distribution of P and Rs
Term
 k < 1
Definition
 reactant concentration is greater than product concentration
Term
 k > 1
Definition
 product concentration is greater than reactant concentration
Term
 concentration values used in k
Definition
 solutions: molar concentrations (M)pure liquids or solids: 1 (H2O = 55.5M)gases: partial pressure (p*atm)
Term
 how constant is k?
Definition
 initial reactant concentration- no effect on kpressure - no effect (except gases)catalyst- no effect on k temperature- does effect k; k is dependent on T
Term
 Neutralization Reaction Summary: Strong acid with strong base - weak acid with strong base- strong acid with weak base-
Definition
 Strong acid with strong base- pH = 7.0weak acid with strong base- pH > 7.0strong acid with weak base- pH < 7.0
Term
 pH for CH3COOH
Definition
 8.72 pH
Term
 main differences between strong acid and strong base versus weak acid and strong base (3)
Definition
 1) weak acid & strong base starts at a higher pH2) inflection point is harder to hit with a weak acid & strong base3) equivalence point is greater than 7.0 with a weak acid & strong base
Term
 Le Chatelier's Principle
Definition
 1884if stress is applied to a system in equilibrium, the system will behave in a manner that relieves the stress to restore equilibrium
Term
 concentration
Definition
 increase in concentration increases the rate of the reaction, so an increase in reactants --> R
Term
 temperature
Definition
 rate of the reaction increases about 2x for each 10C increase in temperature
Term
 exothermic reactions
Definition
 evolve heat since less energy is involved in bonds joining the product atoms together than required to bond reactant atoms
Term
 endothermic reactions
Definition
 absorb heat so forward reactions are favored when heat increases. this is due to more energy being required for forming the product bonds
Term
 pressure
Definition
 rate only effected when the reactants or products are gases. So an increase in pressure is equivalent to the increase in concentration.
Term
 catalyst
Definition
 though it is a reaction enhancer, there is no effect on reactant, so no effect on k
Term
 in the spectrophotometic analysis of commercial aspirin lab we used _____ to analyze the percent composition of commercial grade aspirin
Definition
 visible electromagnetic radiation, or white light
Term
 Plank relationship equation
Definition
 E = hv
Term
 wavelength
Definition
 distance between two crests of a wave
Term
 frequency
Definition
 the number of crests passing a given point in space each second
Term
 wavelength is usually measured in
Definition
 Angstroms ( 1A = 10^-10 m)
Term
 polychromatic light
Definition
 white light, or sunlight, composed of wavelengths of various colors
Term
 monochromatic light
Definition
 light of a single wavelength
Term
 when white light comes in contact with an object it may be
Definition
 1) reflected by 2) absorbed by 3) transmitted through
Term
 light transmitted or reflected through an object will appear as
Definition
 the complementary color
Term
 Beer's Law equation
Definition
 A = abcA: absorbance a: molar absorptivity b: path lengthc: concentration
Term
 in Le Chat lab, the solution with the darkest color has the
Definition
 highest concentration of FeSCN2+
Term
 rate-controlling step
Definition
 the slowest step in the mechanism
Term
 molecularity
Definition
 number of particles that collide
Term
 in the Kinetic Study of an Iodine Clock Reaction lab, the order of reaction and the specific rate constant, k, was determined by
Definition
 the Method of Initial Rates
Term
 In the Kinetic Study of an Iodine Clock Reaction lab, the presence of I2 is detected by
Definition
 observing the deep blue color it forms with the starch indicator
Term
 In the Determination of an Equilibrium Constant lab, why is the cork wrapped in foil
Definition
 to block the gas from escaping through the cork's large pores
Term
 Decantation
Definition
 The separation of a liquid from a solid by careful pouring, allow the solid to settle to the bottom of the container.
Term
 Extraction
Definition
 A separation process used when only one component of a mixture is soluble in a specific added solvent. After adding the solvent, the insoluble components can be recovered by removing the solvent using decantation or filtration.
Term
 Why is water capable of dissolving other substances?
Definition
 The reason for it is because of waters highly polar nature. The electrons in a water molecule aren't distributed equally but are concentrated near the oxygen atom and less concentrated near the hydrogen.
Term
 Electrolyte
Definition
 A substance that conducts electricity when dissolved in water. Strong electrolytes conduct strong ions whereas weak electrolytes do not.
Term
 Solubility
Definition
 The maximum mass of a solute that can dissolve in a mixture.
Term
 Miscibility
Definition
 When both solute and solvent are liquids
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