2. (30 Pts) The Semi-empirical Hückel Approximation May Also Be Used To Describe Covalent

Transcribed Image Text from this Question2. (30 pts) The semi-empirical Hückel approximation may also be used to describe covalent bond formation a) (10 pts) Use the experimental bond formation energy of H, to obtain a value for the Hückel B parameter (expressed in kJ/mol units). b) (10 pts) Use the value of B from part (a) to calculate the energy of the reaction linear-Hz – cyclic-Hs, in which the linear Hz molecule is converted to the cyclic H; molecule c) (10 pts) Discuss the relative stability of the following molecules. Show detailed calculations of x bond formation energy HỌC=CH H2C=CH-CH2 H2C=CH-CH2 2. (30 pts) The semi-empirical Hückel approximation may also be used to describe covalent bond formation a) (10 pts) Use the experimental bond formation energy of H, to obtain a value for the Hückel B parameter (expressed in kJ/mol units) b) (10 pts) Use the value off from part (a) to calculate the energy of the reaction linear-Hy – cyclic-Hs, in which the linear H, molecule is converted to the cyclic H, molecule c) (10 pts) Discuss the relative stability of the following molecules. Show detailed calculations of a bond formation energy HỌC CH” H_C=CH-CH2 HỌC CH-CH=”

Question 4 1 Pts Select All The Solvents/solutions In Which You Would Expect This
Transcribed Image Text from this QuestionQuestion 4 1 pts Select all the solvents/solutions in which you would expect this compound to dissolve: I-z O ہم Dilute aqueous HCI Dilute aqueous sodium bicarbonate Ethyl acetate Dilute aqueous NaOH CS Scanned with CamScanner Select all the solvents/solutions in which you would expect this compound to dissolve: CI. gos ОНІ CI Dilute aqueous NaOH Dilute aqueous sodium bicarbonate Ethyl acetate Dilute aqueous HCI CS Scanned with CamScanner Select all the solvents/solutions in which you would expect this compound to dissolve: OH HO Dilute aqueous NaOH O Dilute aqueous sodium bicarbonate Ethyl acetate c) O Dilute aqueous HifiCamScanner Select all the solvents/solutions in which you would expect this compound to dissolve: O co Dilute aqueous HCI Dilute aqueous sodium bicarbonate Dilute aqueous NaOH Ethyl acetate CS Scanned with CamScanner

References Use The References To Access Important Values If Needed For This Question. Radioactive
Transcribed Image Text from this QuestionReferences Use the References to access important values if needed for this question. Radioactive decay can be described by the following equation In A = In A, – kt where Ao is the original amount of the substance, A is the amount of the substance remaining after time t, and k is a constant that is characteristic of the substance. For the radioactive isotope strontium-80, k is 4.08 x 10- hours? If the original amount of strontium-80 in a sample is 68.2 mg, how much time is needed for the amount of strontium-80 that remains to fall to 39.0 mg? hours Submit Answer

A1.88 G Sample Mixture Of BaCl 2H,0 (molar Mass = 244.3 G/mol) And Na
A1.88 g sample mixture of BaCl 2H,0 (molar mass = 244.3 g/mol) and Na PO4.12H20 (molar mass = 380.2 g/mol) was dissolved in 250 mL water, and after filtration and drying of the resulting barium phosphate precipitate (Ba3(PO4)2. molar mass = 601.9 g/mol), weighed 0.25 g. If a drop of barium chloride solution added to the filtrate yielded a precipitate, then the mass % of the limiting reactant in the sample mixture is equal to:

In The Empirical Formula Of An Oxide Experiment, The Value Of X In MgxO
Chemistry Assignment Writing ServiceTranscribed Image Text from this QuestionIn the empirical formula of an oxide experiment, the value of x in MgxO was found to be 1.5; Calculate the mass (in grams) of MgxO if the mass of magnesium used was 1.55 9. (Molar masses (g/mol): Mg = 24.3, O = 16.0) Select one: O a. 2.37 O b. 1.94 O c. 1.80 O d. 209 O e. 2.23

Question 4. I) Name The Following Compounds, Including Whether The Chiral Centre Is “R”
Transcribed Image Text from this QuestionQuestion 4. i) name the following compounds, including whether the chiral centre is “R” or “S”. CH2-CH3 OH a) b) H C CH2-CH3 C CH3 H Br CH3-CH2-CH2 ii) Name the following compounds, including whether the isomer is E or Z. a) CH3 CH2-CH3 b) H. C=C =C Br CH2-CH2-C1 Br CH2-CH2-CI

Exercise 7 1- What Are The Units For Each Of The Following If The
Transcribed Image Text from this QuestionExercise 7 1- What are the units for each of the following if the concentrations are expressed in moles per liter and the time in seconds? a) rate constant for a zero-order rate law b) rate constant for a first-order rate law c) rate constant for a second-order rate law 2- The reaction 2NO(g) C1: () — 2NOCI (3) was studied at -10°C. The following results were obtained where INO) C1:16 Initial rate 4[Cl] (mol/L) (mol/L) (mol/L.min) 0.10 0.18 A. What is the rate law? 0.10 0.20 0.36 B. What is the value of the rate constant? 0.20 0.20 1.45 Rate. st 0.10 3- A certain reaction has the following general form: aA-B At a particular temperature and [A]o = 2.00 x 102 M, concentration versus time data were collected for this reaction, and a plot of In[A] versus time resulted in a straight line with a slope value of -2.97 10 min” a. Determine the rate law, the integrated rate law, and the value of the rate constant f this reaction b. Calculate the half-life for this reaction. c. How much time is required for the concentration of A to decrease to 2.50 x 102 M2 4- The decomposition of hydrogen iodide on finely divided gold at 150°C is zero order with respect to Hl. The rate defined below is constant at 1.20 x 10-moll. s. 2H1 (2) –H2(g) 1: (g) Rate AND 4 k = 1.22×10-mol/L. a-If the initial HI concentration was 0.250 mol/L, calculate the concentration of HI at 25 minutes after the start of the reaction. How long will it take for all of the 0.250 M HI to decompose? i. in. 5- For the following reaction profile, indicate E Reaction coordinate a) the positions of reactants and products. b) the activation energy. C) AE for the reaction. 6- The reaction (CH3)3CBr OH → (CH3)3COH Br” in a certain solvent is first order with respect to (CH3),CBr and zero order with respect to OH”. In several experiments, the rate constant k was determined at different temperatures. A plot of In(k) versus 1/T was constructed resulting in a straight line with a slope value of -1.10 x 106 K and y- intercept of 33.5. Assume k has units of s! a. Determine the activation energy for this reaction. b. Determine the value of the frequency factor A. c. Calculate the value of k at 25°C.

Geometric Isomers Occur In Some Alkenes. These Isomers Are Called Cis-trans Isomers Because Of
Transcribed Image Text from this QuestionGeometric isomers occur in some alkenes. These isomers are called cis-trans isomers because of the spatial orientation of the atoms or groups of atoms attached to the two carbons that form the double bond. Select the pairs that are cis-trans isomers. Н CH2-CH3 Н Н H3C-CH2-CH2 H H3C CH2-CH3 H3C-CH2 CH2-CH3 H CH3 H3C-CH2 Н H CH3 H3C-CH2 Н Нас н H3C-CH2 H5C CH3 H

Ammonia, NH,, Reacts With Oxygen To Form Nitrogen Gas And Water. 4 NH, (aq)
Transcribed Image Text from this QuestionAmmonia, NH,, reacts with oxygen to form nitrogen gas and water. 4 NH, (aq) 30,(g) 2N,(g) 6H 0(1) If 2.25 g of NH, reacts with 3.38 g of O, and produces 0.350 L of N, at 295 K and 1.00 atm, which reactant is limiting? NH, (aq) 0,8) What is the percent yield of the reaction? percent yield:

Terfenadine Was Used As An Anti-histamine Until It Was Replaced By A Second-generation Product
Terfenadine was used as an anti-histamine until it was replaced by a second-generation product derived from the second compound, fexofenadine, which carries less risk of cardiac arrhythmia. Another common allergy medication is cetirizine. Explain how IR spectroscopy could help distinguish between these drug compounds. For each, identify any chiral centers. Over the counter versions of cetirizine are a racemic mixture. Prescription versions are levocetirizine. What does this suggest about the bioactivity of dextrocetirizine? Draw the prescription form, 2-[2-[4-[(R)-(4-chlorophenyl)-phenyl-methyl]piperazin-1-yl]ethoxy]acetic acid dihydrochloride (there is a reason the IUPAC name for drug compounds aren’t often used). Use the notation R, R’, etc. for any groups too complex to warrant redrawing. Draw a Newman projection for levocetirizine, looking down theC-C bond connecting the chiral center to the highest priority carbon attached to that chiral center. terfenadine C32H41NO2 Fexofenadine C32H39NO4 Cetirizine C21H25ClN2O3

Consider The System At Equilibrium. 2 CO(g) O2(g) = 2 C02(g) How Will
Transcribed Image Text from this QuestionConsider the system at equilibrium. 2 CO(g) O2(g) = 2 C02(g) How will increasing the concentration of CO shift the equilibrium? O to the right to the left no effect How will increasing the concentration of CO, shift the equilibrium? O to the left O no effect O to the right How will decreasing the volume of the container shift the equilibrium? to the left to the right no effect

I Need Help With Calucations (if Any), Graphing (if Any), And The Conclusion. The Results Are In The First Picture.
Transcribed Image Text from this QuestionDistillation Volume (ml) Temperature ( Celsius) Simple Distillation 60 62 63 65 66 67 67 70 71 72 73 81 82 100 100 100 Initial Drop 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Temperature Temperature (Celsius) ( Celsius) Fractional Distillation Fractional Distillation Vigreux Column Glass Tube Column 55 54 55 56 55 57 56 58 56 58 56 59 60 56 61 56 62 59 64 59 66 56 59 68 59 59 99.5 100 73 90 95 100 IKKIKKO Vigreus.com Figure 2 Figure 2.A Notes: 1 Very sophisticated distillation columns may be used to separate mictures with boiling point differences less than 10’C. For instance one of your instructors (Dr. McCallum) once used a so called ‘spinning and column to quantitatively separate a mixture of (CH3) 3 CO M and (CH3) 3COD (D = 2H) whose boiling points differed by Jess than 1 C. It also took 24 hours to perform the distillation of a 10 mi sample and required constant monitoring. Now, chromatography column, gas (GC) or high performance liquid (HPLC)) would be used to separate mixtures having very similar boiling points (see Exp 5. Chromatography 2 The correct positioning of the thermometer ensures that the bp measured is accurate. Initially a very small blue flame is used to remove the very volatile acetone (bp 56 °C), as the acetone is distilled, however, the intensity of the flame must be increased to remove the less volatile water. Bunsen burners are often used for distillation instead of hot plates) because of better control of the heat source. 3 Crystal Violet is an organic dye. See the Extraction Experiment (Exp. 6, p. 26) for a discussion about its unique structure and properties 4 Boiling chips for stones) are smallinen porous solids (often made of Carborundum). When heated the air in ide expands (PVRT) producing a stream of tiny bubbles. These small bubbles promote ‘even boiling then the liquid is heated to the boiling point without these boiling chips many organic liquids undergo very uneven boiling with so called bumping where the solvent produces very large bubbles which results in plashing and lo of liquid. This is another reason Erlenmeyer flasks are used for heating liquids (see 13. in General Laboratory Procedures). Their conical shape minimizes loss of liquid if bumping does occur.