LAB PRACTICAL Flashcards
Measurement estimates
one value beyond the last marking on measurement device
Pharmacokinetics
process by which drug is absorbed, metabolized, eliminated
Catalysis
increase in rate of reaction due to participation of catalyst which lowers activation energy
Order of reaction
determined by coefficient in balanced equation but must be determine EXPERIMENTALLY
Arrhenius Equation
k = Ae^_Ea/RT with R = 0.008314, Ea = activation energy
Greater activation energy means
slower rate
Chemical Kinetics Reaction Rate
Rate = k [Fe3+]m[I-]n (we determined m and n experimentally)
Chemical Kinetics Rate in terms of Triiodide ion
Rate =Δ[I3-] / Δt
What was Fe3+ conmibed with
I- and S2O3 2-
Chemical Kinetics Plot
y = ln(Rate) x = ln([I-]_ with slope = n
Methyl green
green color with seven methyl groups attached, parent dye has 0 groups
Rate of Decolorization [OH-]
[OH-] = 4.5 x 10^-2 x [PO4 3-] / [HPO4 2-]
Rate of Decolorization rate law
rate = k1[dye][H2O] + k2[dye][OH-]
Dye and Absorbance
[dye] = A / e L
-lnA = kobst -lnA0
Graph -lnA versus time
slope is observed rate constant
What is the slope of Kobs vs. [OH-] equal to
= K2, kobs = k1[H2O] + K2[OH-]
K1[H2O] remains constant and does not effect slope (acts as an intercept)
ΔG°= (2 equations)
ΔG° = ΔH° - TΔS°
ΔG° = -RTlnK
If K > 1
ΔG° < 0 and the process will proceed in the forward direction
lnK =
lnK = -ΔH° / RT + ΔS° / R
Ksp is independent or dependent on temperature
dependent
Plot lnK versus 1/T
slope is -ΔH°/R
Ice cream freezes
at a lower temperature than the freezing point of water so rock salt is added
m =
m = moles solute / kg solvent
is molality temperature dependent or independent
independent
Vant Hoff Factor
number of dissolved particles the solute contributes
m = (with VHF)
m = Δtf / I kf
Natural dye in solar cell experiment
TiO2 stained and dye absorbs light from sun to produce flow of electrons
Semi conducting material
TiO2, titanium dioxide
How to electrons flow in solar cell
from TiO2 coated electrode to the counter electrode producing electricity
What does the dye molecule release when it absorbs light
electrons
Mediator
Iodide ion in the electrolyte
Voltage
difference in energy levels of TiO2 and mediator
Current is directly proportional to
amount of light or number of photons absorbed by the dye
Power of solar cell
voltage x current in Watts
Compound in raspberries that plays a role in solar cell
Anthocyanin (carbohydrate)
(REVIEW STRUCTURE)
Chelation
bonding in ions and molecules to metal ions, involves presence of two separate bonds between polydentate ligand and single central metal atom
(REVIEW STRUCTURE)
Mediator oxidation
I- + I2 <–> I3 -
Mediator reduction
6e- + 3I2 <–> 2I3-
Common uses of TiO2
toothpaste and food coloring
Area of solar cell to produce 1 watt?
1 watt = Power Watt x Area
Commercial vinegar contains
5-6% acetic acid
Percent Error =
Absolute Value of Actual - Experimental / Actual x 100
Molarity Calculations
M1V1 = M2V2
Percentage (w/v) acetic acid in vinegar
mol / L x 1L / 1000 mL x 5.00 mL = mol
x mol x g / mol = x g / 5.00 mL = X x 100
Examples of coordination compounds
hemoglobin, vitamin b12, chlorophyll
Ammonia serves as
ligand
Sulfate ion serves as
counter ion
Copper coordination compound formula
Cux(NH3)y(SO4)z x H2O
Color indicator in volumetric analysis of ammonia
methyl orange
Beer Lambert Law
absorption of light as it passes through solution is proportional to the concentration of the absorbing species
Empirical formula
Cu(NH3)4(SO4)
Bonsted-Lowry acid
proton donor
Strong acid
ionizes essentially to completion
Larger Ka
stronger acid
Equivalence point
final solution neutral (equal moles), where amount of base has been added, + 1 drop is light pink, vertical on curve
End point
1 final drop turned light pink
After reaching equivalence point
pH is high due to excess base
Ka =
Ka = [A-][H3O+] / [HA]
Ionization equation
[A-] = [H3O+] because 1:1 mole ratio
Titration data M
MaVa=MbVb
Ma=MbVb / Va
Percent ionization =
% = [H3O+] / Ma x 100
Buffer solution
contains weak acid and conjugate base
Henderson-Hasselbalch
pH = pKa + log [A-] / [HA]
Halfway point
pH 1/2 = pKa
1st derivative
max, equivalence point, intersection with x-axis
2nd derivative
inflection point, change = 0
Saturated solution
in state of dynamic equilibrium between dissolved, dissociated, ionic compound and undissolved solid
The solubility of an ionic compound is
lower than a solution containing a common ion than in pure water
Ksp Barium Nitrate
Ksp = [Ba2+][NO3]2
Dynamic Equilibrium
rate of forward = rate of reverse
Equilibrium constant
Keq = [products] / [reactants]
Equilibrium constant graph
y axis = A/([Fe3+]I [SCN-]I)
x axis = A x ([Fe3+]I + [SCN-]I) / ([Fe3+]I [SCN-]I)
slope = -Keq
Freezing point
temperature when solvent in solution and pure solid have same vapor pressure
Larger Ka
more ionization and stronger
