Interpretation: The percentage compositions of the mixture of isomeric methylbutenes obtained from 2-bromo-2-methylbutane with potassium hydroxide and potassium tert-butoxide needs to be calculated.
Concept Introduction: In the dehydrogenation reaction of 2-bromo-2-methyl butane, mixture of products is formed only if the halogen is asymmetrically located on the carbon skeleton.
2-bromo-2-methyl butane results in the production of 2-methyl-2-butene and 2-methyl-1-butene on reaction with a strong base that is KOH. The elimination reaction is irreversible thus, the ratio of products formed are defined by the relative rates of the formation of two products.
The rate of the formation is determined by the relative free energies of the 2-transition states rather than the free energies of the products itself.
The product formed in higher yield is more substituted
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EBK EXPERIMENTAL ORGANIC CHEMISTRY: A M
- P12D.8 Sketch the EPR spectra of the di-tert-butyl nitroxide radical (4) at 292 K in the limits of very low concentration (at which the averaging effect of electron exchange is negligible), moderate concentration (at which electron exchange effects begin to be observed), and high concentration (at which electron exchange effects predominate). 4 di-tert-butyl nitroxidearrow_forwardCalculate the relative population differences (Nɑ - Nβ)/N for 13C nuclei in fields of (i) 0.50 T, (ii) 2.5 T, and (iii) 15.5 T at 25 °C.arrow_forwardA 400 MHz 'H NMR spectrum of a mixture of common organic solvents consisting of benzene (CHs) 8 7.37; diethyl ether (C4H100) 8 3.49 and 8 1.22; and dichloromethane (CH;Cl2) 8 5.30 is given below. Estimate the relative proportions (mole %) of the 3 components from the integrals in the spectrum. CH3-CH2-0-CH2-CH3 Cl-CH2-CI benzene diethyl ether dichloromethane 'H NMR Spectrum (400 MHz, CDCl, solution) 3.5 3.4 ppm 1.3 12 ppm 8 ppm Compound Mole % benzene diethyl ether dichloromethanearrow_forward
- Show solutionsarrow_forwardAbsorption bands in the region of 1600-1700 cm-1 are often used for quantification of caffeine. What does the bands in this region refer to?arrow_forwardA 400 MHz 'H NMR spectrum of a mixture of common organic solvents consisting of benzene (C,H6) 8 7.37; diethyl ether (C4H,1,0) § 3.49 and 8 1.22; and dichloromethane (CH;Clz) 8 5.30 is given below. Estimate the relative proportions (mole %) of the 3 components from the integrals in the spectrum. CH3-CH2-0- CH2-CH3 CI-CH2-CI benzene diethyl ether dichloromethane 'H NMR Spectrum (400 MHz, CDCI, solution) 3.5 3.4 ppm 1.3 1.2 ppm 7 5 3 2 1 ppm Compound Mole % benzene diethyl ether dichoromethanearrow_forward
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- (a) A sample of body serum is to be analysed for sodium by flame emission spectroscopy. 1.00cm3 aliquot of serum was pipetted into each of two 50.0 cm3 volumetric flasks. The firstflask was diluted to volume with deionised water. The absorbance of this first solution was0.350. To the second flask 10.0 cm3 of a 25.0 ppm sodium standard was added and theflask made up to volume with deionised water. The absorbance of this second solution was0.720.(i) Calculate the concentration of the sodium in the body serum in mg dm–3arrow_forwardIn the fluorescence quenching of rhodamine B dye, the fluorescence decay of rhodamine B in the DMF-solution with ethanol-water mixture was monitored by measuring the 605 nm emission lifetime (decay of intensity over time) after a laser pulse. The lifetime (t) of rhodamine B in absence of quenchers is Do 2.10 ns. Quenching of rhodamine fluorescence by the presence of 2% ethanol- water mixture reduced the lifetime (T) to 1.86 ns. Using the following Stern-Volmer equation, what would be the rhodamine B emission lifetime in ns by changing the ethanol-water to 13 %? (Final answer should be of three significant figures) 1.142 To T = k₁ + k₂+k₂ [Q] k₁ + k₁₂arrow_forward12D.15 At low resolution, the strongest absorption band in the infrared absorption spectrum of 12C¹6O is centred at 2150 cm-¹. Upon closer examination at higher resolution, this band is observed to be split into two sets of closely spaced peaks, one on each side of the centre of the spectrum at 2143.26 cm-¹1. The separation between the peaks immediately to the right and left of the centre is 7.655 cm-¹. Make the harmonic oscillator and rigid rotor approximations and calculate from these data: (a) the vibrational wavenumber of a CO molecule, (b) its molar zero-point vibrational energy, (c) the force constant of the CO bond, (d) the rotational constant B, and (e) the bond length of CO.arrow_forward
- Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning