Chem 6C Comprehensive Review

Post on 23-Jan-2016

290 views 4 download

Tags:

description

Chem

Transcript of Chem 6C Comprehensive Review

All You Can Cram In 3 HoursChem 6C EditionStressed-Out Charlie Lin

And Miles whose last name I can’t spell

If all else fails, since it’s a multiple choice exam, make one of these magical things.

Testimony: I’ve had the same one since high school and its gotten me through exams, GREs, SATs, and pretty much everything... Including the exam I took this morning!

*Multiple choice answer pencil, roll pencil and see what bubble you should fill in!***Results may vary*****If you are loud rolling a pencil you may or may not be removed from the testing premises.

Transition Metals

• Naming– It’ll be a salt so name cation first then anion– The cation or anion will be a complex to name a

complex:• Take all the ligands and put them by their greek name

alphabetically.

• Q5: What is the correct name for [Co(NH3)5Cl](NO3)2?

Reactions

• Q4: Which of the following coordination compounds will form a precipitate when treated with an aqueous solution of AgNO3?a) [Cr(NH3)3Cl3]

b) [Cr(NH3)6]Cl3

c) [Cr(NH3)Cl]SO4

d) Na3[Cr(CN)6]

e) Na3[CrCl6]

Shapes

• 4 Primary shapes– Octahedral

• 6 ligand attachment points groups

– Tetrahedral– Square Planar– Linear

• 2 Ligand attachment points

• Isomers– Geometric– Enantiomers

Maybe skip :P

• Which of the following compounds is chiral?– [Cr(en)2Cl2]+ with cis Cl

– [Cr(en)2(NH3)2]3+ with trans NH3

– [Cr(en)3]3+

– [Cr(en)Cl2(NH3)2]+ with cis Cl and cis NH3

– http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2001/illpres/game.html

Crystal Field Theory

• D-orbital splitting– When 6 identical ligands attached to transition metal ion to

form octahedral complex• T2g orbitals

• Eg orbitals

• Paramagnetic– Unpaired electrons and can be magnetized by external field

• Diamagnetic– No unpaired electrons and cannot be magnetized with

external magnetic field

Which of the following is paramagnetic?• a) Zn(H2O)6

2+

• b) Co(NH3)63+

• c) Ni(CN)42- (square planar)

• d) Mn(CN)63-

Pg 1015 for low spin/high spin chart

26-34

• Some of the first complexes discovered by Werner in the 1890s had the empirical formulas given below. Also are the number of chloride ions per formula unit percipitated by the addition of Ag+ (aq). Explain these observations.

Empirical Formula Number of Cl- per formula unit percipitated by Ag+ (aq)

PtCl2*4NH3 2

PtCl2*3NH3 1

PtCl2*2NH3 0

• Chapter 26-70) Excess Pb2[Fe(CN)6](s) was equilibrated at 25°C with an aqueous solution of NaI(aq). The equilibrium concentrations of I-

(aq) and [Fe(CN)6]4-(aq) were found by chemical analysis to be 0.57 M and 0.11 M, respectively. Estimate the value of Ksp of Pb2[Fe(CN)6](s). The Ksp of PbI2(s) is 9.8x10-9 M3.

• Chapter 26-52) Predict the number of unpaired electrons in

• [Rh(NH3)6]3+ (low spin)

• [FeF6]3-

• [Ir(H2O)6]3+ (low spin)

Buffers (21-20)

• Describe how you would prepare 200.0 mL of a pH = 4.00 buffer solution from a solution of 0.150 M lactic acid, CH3CHOHCOOH (aq), and a solution of 0.100-M barium hydroxide, Ba(OH)2 (aq). Take the pKa of lactic acid to be 3.86.

• Chapter 21-90) What is the pH of the solution that results from the addition of 25.0 mL of 0.200 M KOH(aq) to 50.0 mL of 0.150 M HNO2(aq)?

• Chapter 21-72)A 0.550 gram sample of butyric acid is dissolved in 100.0 mL of water and titrated with 0.100 M NaOH(aq) to the equivalence point. The volume of base consumed is 62.4 mL. Calculate the molecular mass of butyric acid, which has one acidic proton per molecule.

Titrations

• Suppose that 15.0 mL of 0.15 M (C2H5)2NH (Kb 6.90 x 10-4) is titrated with 0.10 M HCI.– What is the pH after the addition of 15.0 mL of

0.10 HCl?– Calculate the pH at the midpoint.– Calculate the pH at the equivalence point.– What is the pH if 1.5 mL of HCl is added past the

equivalence point?

• Chapter 22-88) Calculate the equilibrium chloride ion concentration in a solution made by mixing 50.0 mL of 1.00 M sodium chloride with 50.0 mL of 1.00 M mercury(I) nitrate at 25°C.

Solubility (M3 4&6)

• Calculate the concentration of free iron ion (in molarity) in a 1.0 L solution of 6.0 M NaCN after adding FeCl2 to get 0.35 M FeCl2. Kf of (Fe(CN)6

4-) = 1.0 x 1035

• How many moles of CaF2 will dissolve in 3.0 liters of 0.050 M NaF solution?(Ksp for CaF2 = 2.0 x 10-10)

Qualitative Analysis

Entropy

• Few notes:– ΔS=0 if reaction is reversible– ΔS>0 for a spontaneous process if it’s ΔSsystem +

ΔSsurroundings – ΔS is a state function.

• Calculate the entropy of vaporization of mercury at room temperature, given the following information: Cpm (liquid) = 27.97 J/mol*K, Cpm (gas) = 20.80 J/mol*K, ΔHvap = 58.96 kJ/mol at Tb = 356.7 C.

• Chapter 22-82) The equilibrium constant for the equation

• Is Kf = 0.500 M-1 at 25°C. Calculate the solubility of Zn(OH)2(s) in a 0.10 M NaOH solution at 25°C.

• Chapter 23-84) The Clapeyron-Clausius equation can be used to calculate the equilibrium vapor pressure of a solid by writing ∆Hsub in place of ∆Hvap. Given that ∆Hsub

= 25.2 kJ/mol for CO2(s) and that PCO2 = 1.0 x 102 kPa at -78.6°C, calculate the equilibrium vapor pressure of CO2(s) at -100.0°C.

• Chapter 23-82) Given that for Br2(g) at 25°C, calculate the vapor pressure of bromine at25°C.

Redox

• How to determine whether you’re in an acidic or basic environment– If it’s a metal ion that’s not group 1 or if its already

an acid its probably in an acidic environment– If it’s a metal oxide, metal hydroxide, or an anion

then its probably in a basic environment

• Balance the following equation.• Cr(OH)3 (s) + ClO (aq) > CrO4

2 (aq) + Cl2(g)

• Chapter 24-66) A 3.651 gram sample of a lanthanum sulfate ore is dissolved in nitric acid, and the lanthanum precipitated as La(IO3)3(s) by the addition of 40.00 mL of 0.1105 M KIO3(aq). When an excess of KI(aq) is added to the acidified filtrate, I 2(s) results from the reaction of the remaining IO-

3(aq), as given by

• If it requires 12.65 mL of 0.0650 M Na2S2O3(aq) to react with this I2(s), according to

• Calculate the mass percentage of La2(SO4)3(s) in the sample.

• Chapter 24-60) Peroxyidsulfate, S2O82-(aq), is a

strong oxidizing agent that can oxidize Mn2+ (aq) to MnO4

- (aq); Cr3+ (aq) to Cr2O72-(aq); and

V4+(aq) to V5+(aq). Excess reagent can be destroyed by boiling the solution after oxidation is complete. Balance the equation

Electrochemistry

Which of the following is characteristic of the anode in an electrolysis cell?

• a) It is where reduction occurs.• b) It attracts negative ions.• c) It receives electrons from the wire.• d) It may gain weight during electrolysis.• e) More than one of the above is correct.

• Chapter 25-72) An oxide cell, involving Ag2O(s)│Ag(s) cathode is used to power a wristwatch. The cell is estimated to last 1000 hours while drawing a current of only 0.10 mA. Calculate the mass of silver metal that will be produced over the lifetime of the cell.

• Chapter 25-52) An electrochemical cell is set up so that the reaction described by the equation

• occurs. At 25°C the measured cell voltage is 2.03 V. Calculate the value of ∆Grxn.

Kinetics

• Reaction Rates• Zero Order• First Order• Second Order• Half Lives

Chapter 17-60) A sample of radioactive Na128I is injected into a patient as part of radioiodine treatment of a thyroid condition. If the sample has an activity 10,000 disintegrations per minute at 8 AM, the time of injection, what is the activity at 2 PM the same day? The half-life of iodine-128 is 25.00 minutes.

Chapter 17-54) A reaction of importance in the formation of smog is that between ozone and nitrogen monoxide described by

The rate law for this reaction is Rate of reaction=k[O3][NO]

Given that k=2.99x10-5 M-1s-1 at 310 K, calculate the initial reaction rate when [O3] and [NO] remain essential constant at the values [O3]0=2.0x10-6 M and [NO]0=6.0x10-5 M, owing to continuous production from separate sources. Calculate the number of moles of NO2(g) produced per hour per liter of air.

18-32

• The enzyme catalase catalyzes the decomposition of H2O2 to H2O (l) and O2 (g). Use the following data, determine the value of Rmax and Km, the Michaelis-Menten constant.

[H2O2]0/mmol*L-1 1.0 2.0 5.0

R/mmol*L-1*s-1 1.38 2.67 6.00

Chapter 18-63) A suggested mechanism for the reaction described by

Is 1. 2.

The assumption here is that [NO3] is governed by steady state kinetics. Derive the rate law.

• Chapter 18-58) The reaction

• has the following proposed reaction mechanism

• Determine the rate law.

• The enzyme catalase catalyzes the decomposition of H2O2 to H2O (l) and O2 (g). Use the following data, determine the value of Rmax and Km, the Michaelis-Menten constant.

[H2O2]0/mmol*L-1 1.0 2.0 5.0

R/mmol*L-1*s-1 1.38 2.67 6.00

• The enzyme catalase catalyzes the decomposition of H2O2 to H2O (l) and O2 (g). Use the following data, determine the value of Rmax and Km, the Michaelis-Menten constant. [H2O2]0/mmol*L-1 1.0 2.0 5.0

R/mmol*L-1*s-1 1.38 2.67 6.00