A quantity of the blue solid on the left in Figure 13.7 is placed in an oven and heated for a time. It slowly turns from blue to the white of the solid on the right. What has occurred?
(a) What is the mass percentage of iodine (I2) in a solution containing 0.035 mol I2 in 125 g of CCl4? (b) Seawater contains per 0.0079 g Sr2+ kilogram of water. What is the concentration of Sr2+...
A solution is made containing 14.6 g of CH3OH in 184 g H2O. Calculate (a) The mole fraction of CH3OH, (b) The mass percent of CH3OH, (c) The molality of CH3OH.
A solution is made containing 20.8 g phenol (C6H5OH) in 425 g ethanol (C2H5OH). Calculate (a) The mole fraction of phenol, (b) The mass percent of phenol, (c) The molality of phenol?
(a) What is the molality of a solution formed by dissolving 1.12 mol of KCl in 16.0 mol of water? (b) How many grams of sulfur (S8) must be dissolved in 100.0 g naphthalene (C10H8) to make a 0.12 m...
Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin.
Caffeine (C8H10N4O2) is a stimulant found in coffee and tea. If a solution of caffeine in chloroform (CHCl3) as a solvent has a concentration of 0.0500 m, calculate (a) The percent caffeine by mass,...
(a) What is an ideal solution? (b) The vapor pressure of pure water at is 60 oC is 149 torr. The vapor pressure of water over a solution at 60 oC containing equal numbers of moles of water and...
(a) Calculate the vapor pressure of water above a solution prepared by adding 22.5 g of lactose (C12H22O11) to 200.0 g of water at 338 K. (Vapor-pressure data for water are given in Appendix B.) (b)...
(a) Why does a 0.10 m aqueous solution of NaCl have a higher boiling point than a 0.10 m aqueous solution of C6H12O6? (b) Calculate the boiling point of each solution. (c) The experimental boiling...
Arrange the following aqueous solutions, each by mass in solute, in order of increasing boiling point: glucose (C6H12O6), sucrose (C12H22O11), sodium nitrate (NaNO3)?
What is the osmotic pressure formed by dissolving 44.2 mg of aspirin (C9H8O4) in 0.358 L of water at 25 oC?
Adrenaline is the hormone that triggers the release of extra glucose molecules in times of stress or emergency. A solution of 0.64 g of adrenaline in 36.0 g of CCl4 elevates the boiling point by 0.49...
(a) Why is there no colloid in which both the dispersed substance and the dispersing substance are gases?
A saturated solution of sucrose (C12H22O11) is made by dissolving excess table sugar in a flask of water. There are 50 g of un-dissolved sucrose crystals at the bottom of the flask in contact with...
(a) Which species predominate at equilibrium, reactants or products? (b) Which reaction has the larger rate constant, the forward or the reverse? Explain.
A mixture of 0.10 mol of NO, 0.050 mol of H2, and 0.10 mol of H2O is placed in a 1.0-L vessel at 300 K. The following equilibrium is established: At equilibrium [NO] = 0.062. (a) Calculate the...
A mixture of 1.374 g of H2 and 70.31 g of Br2 is heated in a 2.00 - L vessel at 700 K. These substances react according to At equilibrium the vessel is found to contain 0.566 g of H2. (a) Calculate...
At 1000 K, Kp = 1.85 for the reaction (c) What is the value of Kc for the reaction in part (b)?
As shown in Table 15.2, Kp for the equilibrium is 4.51 Ã 10-5 at 450 oC. For each of the mixtures listed here, indicate whether the mixture is at equilibrium at 450 oC. If it is not at...
At 100 oC, Kc = 0.078 for the reaction In an equilibrium mixture of the three gases, the concentrations of SO2Cl2 and SO2 are 0.108 M and 0.052 M, respectively. What is the partial pressure of Cl2 in...
At 2000 oC the equilibrium constant for the reaction Is Kc = 2.4 Ã 103. If the initial concentration of NO is 0.175 M, what are the equilibrium concentrations of NO, N2, and O2?
At 218 oC, Kc = 1.2 Ã 10-4 for the equilibrium Calculate the equilibrium concentrations of NH3 and H2S if a sample of solid NH4SH is placed in a closed vessel at 218 oC and decomposes until...
A mixture of CH4 and H2O is passed over a nickel catalyst at 1000 K. The emerging gas is collected in a 5.00-L flask and is found to contain 8.62 g of CO, 2.60 g of H2, 43.0 g of CH4, and 48.4 g of...
A mixture of H2, S, and H2S is held in a 1.0 - L vessel at 90 oC and reacts according to the equation: At equilibrium the mixture contains 0.46 g of H2S and 0.40 g H2. (a) Write the...
A sample of nitrosyl bromide (NOBr) decomposes according to the equation An equilibrium mixture in a 5.00-L vessel at 100 oC contains 3.22 g of NOBr, 3.08 g of NO, and 4.19 g of Br2. (a) Calculate...
(a) What is the total pressure in the flask at equilibrium? (b) What is the value of Kp? (c) What could we do to maximize the yield of B?
As shown in Table 15.2, the equilibrium constant for the reaction (a) What are the masses of N2 and H2 in the equilibrium mixture? (b) What was the initial mass of ammonia placed in the vessel? (c)...
(a) Which reaction mixture is at equilibrium? (b) For those mixtures that are not at equilibrium, how will the reaction proceed to reach equilibrium?
(a) Use the reaction quotient to determine the direction the reaction must proceed to reach equilibrium. (b) Calculate the equilibrium partial pressures of the gases. (c) What effect will increasing...
An equilibrium mixture of H2, I2, and HI at 458 oC contains 0.112 mol H2, 0.112 mol I2, and 0.775 mol HI in a 5.00-L vessel. What are the equilibrium partial pressures when equilibrium is...
At 1200 K, the approximate temperature of automobile exhaust gases (Figure 15.15), Kp for the reaction Is about 1 Ã 10-13. Assuming that the exhaust gas (total pressure 1 atm) contains 0.2%...
Assign the proper formal charge to the colored atom in each of the following structures: (a) (b) (c) (d) (e) (f) (g) (h) H-C-H H-C-NH H-C-H
Amines are like ammonia in being weak bases. They do this by using their unshared electron pair to accept a proton. (a) Show the reaction that would take place between trimethyl amine and HCl. (b)...
Write a condensed structural formula for each compound given here. (a) (b) (c) (d)
Rewrite each of the following using bond-line formulas: (a) (b) (c) (CH3)3CCH2CH2CH2OH (d) (e) CH2==CHCH2CH2CH==CHCH3 (f) CH3CH2CH2CCH3 CH3CHCH2CH2CHCH2CH3 CH3 CH3 CHsCH2CHCH2COH CH3 CH2 HC H2
Analyze the statement: For a molecule to be polar, the presence of polar bonds is necessary, but it is not a sufficient requirement.
Although we shall discuss the naming of organic compounds later when we discuss the individual families in detail, one method of naming alkyl halides is so straightforward that it is worth describing...
Two constitutional isomers having molecular formula C4H6O are both symmetrical in structure. In their infrared spectra, neither isomer when in dilute solution in CCl4 (used because it is nonpolar)...
Add curved arrows to the following reactions to indicate the flow of electrons for all of the bond-forming and bond-breaking steps. (a) (b) H.
(a) What is the value of Go for a reaction where Keq = 1? (b) Where Keq = 10? (The change in Go required to produce a 10-fold increase in the equilibrium constant is a useful term to remember.) (c)...
Arrange the following in order of increasing basicity: (a) (b) (c)
Follow the curved arrows and write the products. (a) (b) (c) (d) + BF3 BFs
Carbonyl groups also count for a unit of hydrogen deficiency. What are the indices of hydrogen deficiency for the reactant and for the product in the equation shown at the beginning of Section 4.16...
Write a bond-line formula for each of the following compounds: (a) 1, 4-Dichloropentane (b) sec-Butyl bromide (c) 4-Isopropylheptane (d) 2, 2, 3-Trimethylpentane (e) 3-Ethyl-2-methylhexane (f) 1,...
A spiro ring junction is one where two rings that share no bonds originate from a single carbon atom. Alkanes containing such a ring junction are called spiranes. (a) For the case of bicyclic...
(a) Three different alkenes yield 2-methylbutane when they are hydrogenated in the presence of a metal catalyst. Give their structural formulas and write equations for the reactions involved. (b) One...
The antihistamine Allegra (fexofenadine) has the following structural formula. For any chirality centers in fexofenadine, draw a substructure that would have an (R) configuration. Fexofenadine...
Assign the (R, S) configuration at each chirality center in Darvon (dextropropoxyphene). Darvon
Aspartame is an artificial sweetener. Give the (R, S) designation for each chirality center of aspartame. Aspartame OCH H3N
Although ethyl bromide and isobutyl bromide are both primary halides, ethyl bromide undergoes SN2 reactions more than 10 times faster than isobutyl bromide does. When each compound is treated with a...
Write mechanisms that account for the products of the following reactions: (a) (b) H2O Br HO H20
Draw a hypothetical free-energy diagram for the SN2 reaction of iodide anion with 1-chlorobutane. Label the diagram as in Fig. 6.4, and assume it is exergonic but without specific values for G¡...
What would be the effect of increasing solvent polarity on the rate of each of the following nucleophilic substitution reactions? (a) Nu: + R-L R-Nu+ + :L (b) R-L+ R+ + :L
Write the following as net ionic equations and designate the nucleophile, substrate, and leaving group in each reaction: (a) CH3I + CH3CH2ONa CH3OCH2CH3 + NaI (b) NaI + CH3CH2Br CH3CH2I + NaBr (c) 2...
The reaction of chloroethane with water in the gas phase to produce ethanol and hydrogen chloride has Ho = +26.6 kJ mol-1 and So = +4.81 J K-1 mol-1 at 25oC. (a) Which of these terms, if either,...
Which product (or products) would you expect to obtain from each of the following reactions? In each part give the mechanism (SN1, SN2, E1, or E2) by which each product is formed and predict the...
Competition experiments are those in which two reactants at the same concentration (or one reactant with two reactive sites) compete for a reagent. Predict the major product resulting from each of...
In contrast to SN2 reactions, SN1 reactions show relatively little nucleophile selectivity. That is, when more than one nucleophile is present in the reaction medium, SN1 reactions show only a slight...
Acid-catalyzed dehydration of either 2-methyl-1-butanol or 3-methyl-1-butanol gives 2-methyl-2-butene as the major product. Write plausible mechanisms that explain these results.
Show how you might synthesize ethynylbenzene from methyl phenyl ketone.
Outline all steps in a synthesis of propyne from each of the following: (a) CH3COCH3 (b) CH3CH2CHBr2 (c) CH3CHBrCH2Br (d) CH3CH==CH2
Rank the following cycloalkenes in order of increasing stability.
Write the structure of compound A, used in this synthesis of the perfume ingredient (Z)-jasmone. (Lindlar's catalyst) (Z)-Jasmone
Starting with ethyne, outline syntheses of each of the following. You may use any other needed reagents, and you need not show the synthesis of compounds prepared in earlier parts of this problem....
Heats of hydrogenation of three alkenes are as follows: 2-methyl-1-butene (-119 kJ mol-1) 3-methyl-1-butene (-127 kJ mol-1) 2-methyl-2-butene (-113 kJ mol-1) (a) Write the structure of each alkene...
Write structural formulas for all the products that would be obtained when each of the following alkyl halides is heated with sodium ethoxide in ethanol. When more than one product results, you...
Write structural formulas for all the products that would be obtained when each of the following alkyl halides is heated with potassium tert-butoxide in tert-butyl alcohol. When more than one product...
1-Bromobicyclo [2.2.1] heptane does not undergo elimination (below) when heated with a base. Explain this failure to react. (Construction of molecular models may help.) Br
Starting with an appropriate alkyl halide and base, outline syntheses that would yield each of the following alkenes as the major (or only) product: (a) (b) (c) (d) (e)
Give the products that would be formed when each of the following alcohols is subjected to acid-catalyzed dehydration. If more than one product would be formed, designate the alkene that would be the...
Compounds L and M have the molecular formula C7H14, Compounds L and M are optically inactive, are nonresolvable, and are diastereomers of each other. Catalytic hydrogenation of either L or M yields...
Consider the interconversion of cis-2-butene and trans-2-butene. (a) What is the value of Ho for the reaction cis-2-butene : trans-2-butene? (b) Assume Ho Go. What minimum value of DG would you...
(a) Outline a likely mechanism for the solvomercuration step of the ether synthesis just shown. (b) Show how you would use solvomercuration-demercuration to prepare tertbutyl methyl ether. (c) Why...
Outline mechanisms for the following addition reactions: (a) (b) (c) HBr HI
Provide mechanistic explanations for the following observations: (a) (b) HCI CI CI Cl CI HCI
Starting with 2-methylpropene (isobutylene) and using any other needed reagents, outline a synthesis of each of the following: (a) (b) (c) (d) OR Br CI HO
Farnesene (below) is a compound found in the waxy coating of apples. (a) Give the structure and IUPAC name of the product formed when farnesene is allowed to react with excess hydrogen in the...
Use your answers to the preceding problem to predict the stereochemical outcome of the addition of bromine to maleic acid and to fumaric acid. (a) Which dicarboxylic acid would add bromine to yield a...
Outline all steps in a mechanism showing how 2, 3-dimethyl-2-butanol is formed in the acid-catalyzed hydration of 3, 3-dimethyl-1-butene.
Alkyl halides add to alkenes in the presence of AlCl3; yields are the highest when tertiary halides are used. Predict the outcome of the reaction of tert-pentyl chloride (1-chloro-2,...
A naturally occurring antibiotic called mycomycin has the structure shown here. Mycomycin is optically active. Explain this by writing structures for the enantiomeric forms of mycomycin....
An optically active compound D has the molecular formula C6H10 and shows a peak at about 3300 cm-1 in its IR spectrum. On catalytic hydrogenation D yields E (C6H14). Compound E is optically inactive...
Propose a mechanism that explains the following transformation. H2SO4 OH
Pheromones (Section 4.7) are substances secreted by animals that produce a specific behavioral response in other members of the same species. Pheromones are effective at very low concentrations and...
(a) Based on the following information, draw three-dimensional formulas for A, B, and C. Reaction of cyclopentene with bromine in water gives A, Reaction of A with aqueus NaOH (1 equivalent, cold)...
Triethylamine, (C2H5)3N, like all amines, has a nitrogen atom with an unshared pair of electrons. Dichlorocarbene also has an unshared pair of electrons. Both can be represented as shown below. Draw...
Write a mechanism for the following reaction. cat. H.SO OMe
Draw the most stable chair conformation of 1-bromo-2-chlorocyclohexane, if the coupling constant between hydrogens on C1 and C2 was found to be 7.8 Hz (J1,2 = 7.8 Hz).
In contrast to 2-methylbutane and neopentane, the mass spectrum of 3-methylpentane (not given) has a peak of very low relative abundance at - 15. It has a peak of very high relative abundance at -...
Assume that in a certain 1H NMR spectrum you find two peaks of roughly equal intensity. You are not certain whether these two peaks are singlets arising from uncoupled protons at different chemical...
What are the expected ratios of the Peaks for the following compounds? (a) (b) Mt.M: 2, and M +4 Br Cl
How many 1H NMR signals (not peaks) would you predict for each of the following compounds? (Consider all protons that would be chemical shift nonequivalent.) (a) (b) (c) (d) (e) (f) (g) (h) (i)
Propose structures for compounds O and P that are consistent with the following information. H2(2 equiv.C&12 0 DEPT CH2 CH (ppm) 13C NMR for Compound O 26.0 124.5
How many signals would each compound give in its 1H NMR spectrum? (a) CH3OCH3 (b) (c) (d) 2, 3 - Dimethyl-2-butene (e) (Z)-2-Butene (f) (E)-2-Butene o OCH
Acetic acid has a mass spectrum showing a molecular ion peak at m/z 60. Other unbranched monocarboxylic acids with four or more carbon atoms also have a peak, frequently prominent, at m/z 60. Show...
(a) Show that replacing each of the CH2 protons by some group Q in the (S) enantio-mer of 2-butanol leads to a pair of diastereomers, as it does for the (R) enantiomer. (b) How many chemically...
The relative chemical shifts of the doublet and triplet of 1, 1, 2-trichloroethane (Fig. 9.4) and 1, 1, 2, 3, 3-pentachloropropane (Fig. 9.21) are reversed. Explain this.
Deduce the structure of the compound that gives the following 1H, 13C, and IR spectra (Figs. 9.54-9.56). Assign all aspects of the 1H and 13C spectra to the structure you propose. Use letters to...
Deduce the structure of the compound that gives the following 1H, 13C, and IR spectra (Figs. 9.57-9.59). Assign all aspects of the 1H and 13C spectra to the structure you propose. Use letters to...