A solution contains 0.0653 g of a compound in 8.31 g of ethanol. The molality of the solution is 0.0368 m. Calculate the molecular mass of the compound.
For each of the following molecular formulas, determine the number of elements of unsaturation, and draw three examples. (a) C4H4Cl2 (b) C4H8O (c) C6H8O2 (d) C5H5NO2 (e) C6H3NClBr
An object of mass 2.0 g suspended from the end of a spring has a vibrational frequency of 3.0 Hz. Calculate the force constant of the spring.
Calculate (a) The thermal wavelength, (b) The translational partition function of an Ar atom in a cubic box of side 1.00 cm at (i) 300 K and (ii) 3000 K.
Suggest a sequence of reactions suitable for preparing each of the following compounds from the indicated starting material. You may use any necessary organic or inorganic reagents. (a) 1-Propanol...
Methane is a by-product of a number of natural processes (such as digestion of cellulose in ruminant animals, anaerobic decomposition of organic waste matter) and industrial processes (such as food...
How could you use Diels?Alder reactions to prepare the following products? Show the starting diene and dienophile in each case. (a) (b) CN C (c) (d) H.
The equilibrium constant for the reaction, 12(s) + Br2 (g) 2 IB r (g) is 0.164 at 25C. (a) Calculate rG for this reaction. (b) Bromine gas is introduced into a container with excess solid iodine. The...
Start from the Maxwell-Boltzmanns distribution and derive an expression for the most probable speed of a gas of molecules at a temperature T. Go on to demonstrate the validity of the equipartition...
Show that the ratio t1/2/t3/4 where 1112 is the half-life and 13/4is the time for the concentration of A to decrease to t of its initial value (implying that t3/4 < t1/2) can be written as a function...
Given that tG = -212.7 kJ mol-1 for the reaction in the Daniell cell at 25C, and b (CuS04) = 1.0 x 10-3 mol kg-i and b (ZnS04) = 3.0 x 10-3 mol kg-I, calculate (a) The ionic strengths of the...
Sight down the C-2C-3 bond, and draw Newman projection formulas for the (a) Most stable conformation of 2, 2-dimethylbutane (b) Two most stable conformations of 2-methylbutane (c) Two most stable...
Find an expression for the change in entropy when two blocks of the same substance and of equal mass, one at the temperature Th and the other at T" are brought into thermal contact and allowed to...
Hemoglobin (abbreviated Hb) is a protein that is responsible for the transport of oxygen in the blood of mammals. Each hemoglobin molecule contains four iron atoms that are the binding sites for O2...
What product would you expect from a Robinson annulations reaction of 2-methyl-1, 3-cyclopentanedione with3-buten-2-one? -CH + H%3DH 2-Methyl-1,3-cyclo- pentanedione 3-Buten-2-one
Give equations for the synthesis of a. CH3CH2CH2CO2H from CH3CH2CH2CH2OH b. CH3CH2CH2CO2H from CH3CH2CH2OH (two ways) c. d. e. CH3OCH2CO2H from f. Cl CO,H from Cl CH CO. from CN CHCH, (two steps)...
Identify the compound with molecular formula C7H14O that gives the following proton-coupled 13C NMR spectrum. 80 60 40 20 o (ppm) frequency
For the thermal decomposition Of F2O by the reaction 2 F2O (g) 2 Fl (g) + 0z (g),) Czarnowski and H) Schumacher (Chem. Phys. Lett. 17, 235 (1972)) have suggested the following mechanism: (a) Using...
Predict the products of the following reactions. (a) allyl bromide + cyclohexyl magnesium bromide (b) cyclopentadiene + anhydrous HCI (c) 2-methylpropene + NBS, light (d) Furan + trans 1,...
Kevlar, a nylon polymer prepared by reaction of 1, 4-benzenedicarboxylic acid (Terephthalic acid) with 1, 4-benzenediamine (p-phenylendiamine), is so strong that its used to make bulletproof vests....
Draw all reasonable electron-dot formulas for the nitronium ion (NO2+), the electrophile in aromatic nitrations. Show any formal charges. Which structure is favored and why? (See Secs. 1.11 and 1.12.)
The equilibrium constant for the reaction N2 (g) + O,(g) ;:='02NO(g) is 1.69 x 10-3 at 2300 K. A mixture consisting of 5.0 g of nitrogen and 2.0 g of oxygen in a container of volume 1.0 dm3 is heated...
When B3-carotene is oxidized in vivo, it breaks in half and forms two molecules of retinal (vitamin A), which is a precursor to the pigment in the retina responsible for vision (Impact I14,J). The...
Compounds known as lactones, which are cyclic esters, are formed on BaeyerVilliger oxidation of cyclic ketones. Suggest a mechanism for the BaeyerVilliger oxidation shown.
I.D. Chapple-Sokol, Cl Giunta, and R.G. Gordon (J Electrochem Sac 136,2993 (1989)) proposed the following radical chain mechanism for the initial stages of the gas-phase oxidation of silane by...
The following reaction involves a conjugate addition reaction followed by an intra molecular Claisen condensation. Write both steps, and show theirmechanisms. CO2CH3 (CH3i>CuLi -CEC-CO2CH3 H
Tartaric acid [HO2CCH(OH)CH(OH)CO2H] was an important compound in the history of stereochemistry. Two naturally occurring forms of tartaric acid are optically inactive. One optically inactive form...
The chemistry of derivatives of trans-decalin is of interest because this ring system is part of the structure of steroids. Make models of the brominated systems (i and ii) to help you answer the...
The NO molecule has a doubly degenerate electronic ground state and a doubly degenerate excited state at 121.1 Cm-I Calculate the electronic contribution to the molar heat capacity of the molecule at...
The final step in an attempted synthesis of laurene, a hydrocarbon isolated from the marine alga Laurencia gianduliferu, involved the Wittig reaction shown. The product obtained, however, was not...
Describe the 1H NMR spectrum you would expect for each of the following compounds, using relative chemical shifts rather than absolute chemical shifts: a. BrCH2CH2Br b. CH3OCH2CH2CH2Br c. d. e. f. g....
When 2-heptyne was treated with aqueous sulfuric acid containing mercury(II) sulfate, two products, each having the molecular formula C7H14O, were obtained in approximately equal amounts. What are...
Succinct anhydride, the structure of which is shown, is a cyclic anhydride often used in Friedel-Crafts acylations. Give the structure of the product obtained when benzene is acylated with succinct...
What product(s) would you expect from the methanolysis of the iodocyclohexane derivative given as the reactant in Practice Problem 6.8? In Problem 6.8 CH3 (CH3)3 I H20 SN1
By what factor does the number of available configurations increase when 100 J of energy is added to a system containing 1.00 mol of particles at constant volume at 298 K?
Express the equilibrium constant of a gas-phase reaction A + 3 B ~ 2 C in terms of the equilibrium value of the extent of reaction, ~, given that initially A and B were present in stoichiometric...
Show that the following mechanism can account for the rate law of the reaction in Problem 22.11: What further tests could you apply to verify this mechanism? HCl + HCl K, HCI + CH,CH=CH, complex...
Evaluate (ClS/ClV)]' for (a) A van der Waals gas, (b) A Dieterici gas (Table 1.7). For an isothermal expansion, for which kind of gas (and a perfect gas) will /).5be greatest? Explain your conclusion.
The table shown here lists the molar heats of vaporization for several organic compounds. Use specific examples from this list to illustrate how the heat of vaporization varies with (a) Molar mass,...
Confirm that the z-component of orbital angular momentum is a basis for an irreducible representation of A, symmetry in C3v'
Nitrites (RC ? N) react with Grignard reagents (R'MgBr). The reaction product from 2-methyipropanenitrile with methyl magnesium bromide has the following spectroscopic properties. Propose a...
Suggest a mechanism by which ?-ionone is transformed into ?-ionone on treatment with acid. H3o -Ionone B-Ionone
Estimate the contribution of the spin to the molar entropy of a solid sample of a d-metal complex with S =3/2
Appendix B lists the vapor pressure of water at various external pressures. (a) Plot the data in Appendix B, vapor pressure (torr) versus temperature (oC). From your plot, estimate the vapor pressure...
You take three compounds, each consisting of two elements (X, Y, and/ or Z) and decompose them to their respective elements. To determine the relative masses of X, Y, and Z, you collect and weigh the...
Which reducing agent, LiAlH4 or NaBH4, would you use to carry out the following practice problem 12.3 transformations? (a) (b) (c) (d) (e) HO HO HO OMe OMe OH
In light-harvesting complexes, the fluorescence of a chlorophyll molecule is quenched by nearby chlorophyll molecules. Given that for a pair of chlorophyll a molecules Ra = 5.6 nm, by what distance...
How would you prepare the following compounds starting with an appropriate carboxylic acid and any other reagents needed? (Reddish brown =Br.) (a) (b)
The exchange of deuterium between acid and water is an important type of equilibrium, and we can examine it using spectroscopic data on the molecules. Calculate the equilibrium constant at (a) 298 K...
The sex attractant of the female winter moth has been identified as the tetraene CH3(CH2)8CHCHCH2CHCHCH2CHCHCHCH2. Devise a synthesis of this material from 3, 6-hexadecadien-1-ol and allyl alcohol.
Write the mechanism of the acid-catalyzed cleavage of tert-butyl cyclohexyl ether to yield Cyclohexanol and 2-methylpropene.
Mesitylene (1, 3, 5-trimethylbenzene) is the most stable of the trimethylbenzene isomers. Can you think of a reason why? Which isomer do you think is the least stable? Make a molecular model of each...
The flux of visible photons reaching Earth from the North Star is about 4 x 103 mm-2 S-I. Of these photons, 30 per cent are absorbed or scattered by the atmosphere and 25 per cent of the surviving...
The medicinal thermometer commonly used in homes can be read 0.1F, whereas those in the doctor's office may be accurate to 0.1C. In degrees Celsius, express the percent error expected from each of...
In a similar experiment, unlabeled 4-butanolide was allowed to stand in an acidic solution in which the water had been labeled with 18O. When the lactone was extracted from the solution after 4 days,...
Consider a system with energy levels Ej =jE and N molecules. (a) Show that if the mean energy per molecule is ae, then the temperature is given by Evaluate the temperature for a system in which the...
The diffusion coefficient for CCl4 in heptane is 3.17 X 10-9 m2 S-1' How long does a molecule take to jump through about one molecular diameter (approximately the fundamental jump length for...
Arrange these compounds in order of increasing SN2 reaction rate: CI Br CI Br
Which one of the dichlorobenzene isomers does not have a dipole moment? Which one has the largest dipole moment? Compare your answers with the dipole moments calculated using the molecular-modeling...
Adiponitrile, a starting material used in the manufacture of nylon, can be prepared in three steps from 1, 3-butadiene. How would you carry out thissynthesis? 3 steps H2C=CHCH=CH2 N=CCH2CH2CH2CH2C=N...
The running engine of an automobile produces carbon monoxide (CO), a toxic gas, at the rate of about 188 g CO per hour. A car is left idling in a poorly ventilated garage that is 6.0 m long, 4.0 m...
Sabinene is a monoterpene found in the oil of citrus fruits and plants. It has been synthesized from 6-methyl-2, 5-heptanedione by the sequence that follows. Suggest reagents suitable for carrying...
The wave function of a many-electron closed-shell atom can expressed as a Slater determinant (Section 10Ab). A useful property of determinants is that interchanging any two rows or columns changes...
Estimate the orders of magnitude of the partition functions involved in a rate expression. State the order of magnitude of q INA, qR, qV, qE for typical molecules. Check those in the collision of two...
Account for Le Chatelier's principle in terms of thermodynamic quantities.
Write an equation, using the curved-arrow notation, for the acid-base reaction that will take place when each of the following are mixed. If no appreciable acid-base reaction takes place, because the...
A, B, and C are alkynes. Elucidate their structures and that of D using the following reaction roadmap. H2. Pt H2, Pt (CBH14) (C3H4) IR: 3300 cm (1) O3 (2) HOAc H2. Pt (C&H12) (C3H,B) (1) Os (2)...
Provide a detailed mechanism for each of the following reactions. Include contributing resonance structures and the resonance hybrid for the arenium ion intermediates. (a) (b) (c) HNO HSO NO2 Br Bra,...
Show that the function xyz has symmetry species AI in the group D2.
The viscosity of a chlorofluorocarbon (CFC) was measured by comparing its rate of flow through a long narrow tube (using Poiseuille formula) with that of argon. For the same pressure differential,...
In most of its ionic compounds, cobalt is either Co(II) or Co(III). One such compound, containing chloride ion and waters of hydration, was analyzed, and the following results were obtained. A...
A mixture of Fe2O3 and FeO was found to contain 72.00% Fe by mass. What is the mass of Fe2O3 in 0.500 g of this mixture?
Muscarine is a poisonous substance present in the mushroom Amanita muscaria. Its structure is represented by the constitution shown.
A substance known to have a cubic unit cell gives reflections with radiation of wavelength 137 pm at the glancing angles 10.7, 13.6, 17.7, and 21.9. The reflection at 17.7" is known to be due to the...
If methanol rather than water is added at the end of a Hell-Volhard-Zelinskii reaction, an ester rather than an acid is produced. Show how you could carry out the following transformation, and...
N-Methylpyrrolidine has a boiling point of 81 °C, and piperidine has a boiling point of 106 °C. (a) Explain this large difference (25 °C) in boiling point for these two isomers. (b)...
Tyramine is an alkaloid found, among other places, in mistletoe and ripe cheese. How would you synthesize tyramine from benzene? Fromtoluene CH2CH2NH2 Tyramine
Name each of the following compounds according to substitutive IUPAC nomenclature: (a) (CH3)2CHCH2CH2CH2Br (b) (CH3)2CHCH2CH2CH2OH (c) Cl3CCH2Br (d) (e) CF3CH2OH (f) (g) (h) (i) Cl2CHCHBr CI OH ,
The Einstein frequency is often expressed in terms of an equivalent temperature E, where E= hv/k, Confirm that E has the dimensions of temperature, and express the criterion for the validity of the...
Consider the decay series A B C D where A, B, and C are radioactive isotopes with half-lives of 4.50 s, 15.0 days, and 1.00 s, respectively, and D is nonradioactive. Starting with 1.00 mole of A,...
Give the ground-state electron configurations of (a) CIF, (b) CS, and (c) 0-2.
Explain the observation that attempted Fischer esterification of 2, 4, 6-tri-methylhenzoic acid with methanol and HC1 is unsuccessful. No ester is obtained, and the acid is recovered unchanged. What...
Treat carbon monoxide as a perfect gas and apply equilibrium statistical thermodynamics to the study of its properties, as specified below, in the temperature range 100-1000 K at 1 bar. V = 2169.8...
Some chemists believe that satisfaction of the octet rule should be the top criterion for choosing the dominant Lewis structure of a molecule or ion. Other chemists believe that achieving the best...
The relative rates of reaction of ethane, toluene, and ethylbenzene with bromine atoms have been measured. The most reactive hydrocarbon undergoes hydrogen atom abstraction a million times faster...
Consider the following data concerning four different substances. Label the four substances as either ionic, network, metallic, or molecular solids. Conducts Electricity as a Solid Othe Properties No...
Nordic Company issued bonds with the following provisions: Maturity value: $ 60,000,000 Interest: 7.9 percent per annum payable semi- annually each June 30 and December 31 Terms: Bonds dated January...
Compound Y (C8H4O3) dissolves slowly when warmed with aqueous sodium bicarbonate. The IR spectrum of Y has strong peaks at 1779 and at 1854 cm-1. The broadband proton-decoupled 13C spectrum of Y...
Calculate the magnitude and direction of the dipole moment of the following arrangement of charges in the xy-plane: 4e at (0, 0), -2e at (162 pm, 0), and -2e at an angle of30 from the x-axis and a...
What products would you obtain from reaction of 1-penlanol with the following reagents? (a) PBr3 (b) SOCl2 (c) CrO3, H20, H2SO4 (d) PCC
A student wanted to use the Williamson ether synthesis to make (R)-2-ethoxybutane. He remembered that the Williamson synthesis involves an SN2 displacement, which takes place with inversion of...
Thallium, a neurotoxin, is the heaviest member of Group 13 of the periodic table and is found most usually in the +1 oxidation state. Aluminum, which causes anaemia and dementia, is also a member of...
The collision frequency z of a molecule of mass m in a gas at a pressure pis z = 4(J (kTlnm) 1/2p/kT, where o is the collision cross-section. Find an expression for the collision-limited lifetime of...
Values of measured bond energies may vary greatly depending on the molecule studied. Consider the following reactions: NCl3(g) NCl2(g) + Cl(g) H = 375 kJ/ mol ONCl(g) NO(g) + Cl(g) H = 158 kJ/ mol...
Show how you would synthesize each compound using methylenecyclohexane as your starting material. (a) (b) (c) (d) (e) (f) (g) (h) (i) methylenecyclohexane OH , Cl OH
Circle the functional groups in the following structures. State to which class (or classes) of compounds the structure belongs. (a) CH2=CHCH2COOH3 (b) CH3OCH3 (c) CH3CHO (d) CH3CONH2 (e) CH3NHCH3 (f)...
Draw structures for the enol tautomers of the following compounds: (a) Cyclopentanone (b) Methyl thioacetate (c) Ethyl acetate (d) Propanal (e) Acetic acid (f) Phenyl acetone
Ribose, an essential part of ribonucleic acid (RNA), has the following structure: (a) How many chirality centers does ribose have? Identify them. (b) How many stereo isomers of ribose are there? (c)...
What values off may occur in the terms (a) 3D, (b) 4D, (c) 2G? How many states (distinguished by the quantum number MJ) belong to each level?
F. Luo, G.c. McBane, G. Kim, cr. Giese, and W.R. Gentry (J. Chem. Phys. 98, 3564 (1993)) reported experimental observation of the He2 complex, a species that had escaped detection for a long time....