(a)
Interpretation:
The mechanism for the addition of a proton from trifluoromethanesulfonic acid to the
Concept introduction:
Carbon-carbon double and triple bonds are electron-rich. They can undergo heterolytic bond breaking. The pi bond can break, and the electron pair can be used to form a bond with an electrophile such as a proton. The electrophile bonds to one of the carbon atoms. The other carbon atom gets a 1+ charge and is called a carbocation. The reaction mechanism is drawn by showing the movement of electron pairs with curved arrows. The curved arrow starts from an electron-rich atom or center of an electron-rich region (a pi bond) and ends on an electron-poor atom, an electrophile, to show the formation of a new sigma bond. If a pi bond is formed, the arrow must end in the region between the corresponding atoms.
(b)
Interpretation:
It is to be determined which of the two carbocations formed on the addition of a proton to the given alkyne is more stable.
Concept introduction:
Carbocations are positively charged carbon atoms that are electron poor. The carbon is two electrons short of an octet. The charge and the incomplete octet make the carbocation an unstable species. The stability of a carbocation depends on the number of alkyl groups bonded to it and increases in the order

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Chapter 7 Solutions
EBK GET READY FOR ORGANIC CHEMISTRY
- (2 pts) WSe2 is an ionic compound semiconductor that can be made to be p-type or n-type.What must happen to the chemical composition for it to be p-type? What must happen tothe chemical composition for it to be n-type?arrow_forward8. (2 pts) Silicon semiconductors have a bandgap of 1.11 eV. What is the longest photon wavelength that can promote an electron from the valence band to the conduction band in a silicon-based photovoltaic solar cell? Show all work. E = hv = hc/λ h = 6.626 x 10-34 Js c = 3.00 x 108 m/s 1 eV 1.602 x 10-19 Jarrow_forwardA solution containing 100.0 mL of 0.155 M EDTA buffered to pH 10.00 was titrated with 100.0 mL of 0.0152 M Hg(ClO4)2 in a cell: calomel electrode (saturated)//titration solution/Hg(l) Given the formation constant of Hg(EDTA)2-, logKf= 21.5, and alphaY4-=0.30, find out the cell voltage E. Hg2+(aq) + 2e- = Hg(l) E0= 0.852 V E' (calomel electrode, saturated KCl) = 0.241 Varrow_forward
- From the following reduction potentials I2 (s) + 2e- = 2I- (aq) E0= 0.535 V I2 (aq) + 2e- = 2I- (aq) E0= 0.620 V I3- (aq) + 2e- = 3I- (aq) E0= 0.535 V a) Calculate the equilibrium constant for I2 (aq) + I- (aq) = I3- (aq). b) Calculate the equilibrium constant for I2 (s) + I- (aq) = I3- (aq). c) Calculate the solubility of I2 (s) in water.arrow_forward2. (3 pts) Consider the unit cell for the spinel compound, CrFe204. How many total particles are in the unit cell? Also, show how the number of particles and their positions are consistent with the CrFe204 stoichiometry - this may or may not be reflected by the particle colors in the diagram. (HINT: In the diagram, the blue particle is in an interior position while each red particle is either in a corner or face position.)arrow_forwardFrom the following potentials, calculate the activity of Cl- in saturated KCl. E0 (calomel electrode)= 0.268 V E (calomel electrode, saturated KCl)= 0.241 Varrow_forward
- Calculate the voltage of each of the following cells. a) Fe(s)/Fe2+ (1.55 x 10-2 M)//Cu2+ (6.55 x 10-3 M)/Cu(s) b) Pt, H2 (0.255 bar)/HCl (4.55 x 10-4 M), AgCl (sat'd)/Ag Fe2+ +2e- = Fe E0= -0.44 V Cu2+ + 2e- = Cu E0= 0.337 V Ag+ + e- = Ag E0= 0.799 V AgCl(s) + e- = Ag(s) + Cl- E0= 0.222 V 2H+ + 2e- = H2 E0= 0.000 Varrow_forwardA solution contains 0.097 M Ce3+, 1.55x10-3 M Ce4+, 1.55x10-3 M Mn2+, 0.097 M MnO4-, and 1.00 M HClO4 (F= 9.649 x 104 C/mol). a) Write a balanced net reaction that can occur between species in this solution. b) Calculate deltaG0 and K for the reaction. c) Calculate E and deltaG for the conditions given. Ce4+ + e- = Ce3+ E0= 1.70 V MnO4- + 8H+ + 5e- = Mn2+ + 4H2O E0= 1.507 Varrow_forward1. Provide a step-by-step mechanism for formation of ALL STEREOISOMERS in the following reaction. Na HCO3 (Sodium bicarbonate, baking soda) is not soluble in CH2Cl2. The powder is a weak base used to neutralize strong acid (pKa < 0) produced by the reaction. Redraw the product to show the configuration(s) that form at C-2 and C-4. Br2 OH CH2Cl2 Na* HCO3 Br HO OH + Na Br +arrow_forward
- 2. Specify the solvent and reagent(s) required to carry out each of the following FGI. If two reagent sets must be used for the FGI, specify the solvent and reagent(s) for each reagent set. If a reaction cannot be carried out with reagents (sets) class, write NP (not possible) in the solvent box for reagent set #1. Use the letter abbreviation for each solvent; use a number abbreviation for reagent(s). Solvents: CH2Cl2 (A); H₂O (B); Reagents: HBr (1); R₂BH (6); H2SO4 (2); CH3OH (C); Br₂ (3); CH3CO₂H (D) NaHCO3 (4); Hg(OAc)2 (5); H₂O2/HO (7); NaBH4 (8) Reagent Set #1 Reagent Set #2 FGI + enant OH Solvent Reagent(s) Solvent Reagent(s)arrow_forwardGermanium (Ge) is a semiconductor with a bandgap of 2.2 eV. How could you dope Ge to make it a p-type semiconductor with a larger bandgap? Group of answer choices It is impossible to dope Ge and have this result in a larger bandgap. Dope the Ge with silicon (Si) Dope the Ge with gallium (Ga) Dope the Ge with phosphorus (P)arrow_forwardWhich of the following semiconductors would you choose to have photons with the longest possible wavelengths be able to promote electrons to the semiconductor's conduction band? Group of answer choices Si Ge InSb CdSarrow_forward
