Chemistry Questions and Answers May 13, 2020

Draw the major organic product generated in the reaction below. Pay particular attention to regio and stereochemical detail. CH 1. CH,COH 2. H, HO

2. Folic acid is normally given to pregnant women, at the same time antagonists to folic acid are used for the treatment of some types of cancer. Explain why? 3. There is an increase in clothes made of wool when ironed while ironing has no effects on silky clothes, why? 4. Classify the following as either releasing or demanding energy: a.

Synthesis Problem 6. Consider a chemical reaction where A as (a) Use na, n, nc to represent the populations of A, B, and C. Write down the coupled rate equations describing the populations of A, B, and C as a function of time. (b) Find the eigenvalues of the coefficient matrix in terms of ki, k2, and k3. (You should get k, (k2 k3), and 0) (c)

Below is a Table showing the resuits from a Jar test conducted to determine the optimal dosage of alum to treat a specific surface water. Applying the definition of optimal dosage, the results of this experiment show that the optimal dosage was most closely Table Jar Testing Results (2.0 Lor Raw Water was treated in each Jar) Jar 1 Jar 2 Jar 3 Jar

Calculate the temperature (in kelvins) at which the sign of AGO changes from positive to negative for the reaction below. This corresponds to the temperature at which K 1 changes to K1. Assume that AH and AS are constant and do not change with temperature. 2CO(g) 2NO(g) 2CO(g) N(g) AH 747 kJmol and AS 198 JK mol

At physiological pH, the 06methylguanineT wobble base pair predominates. Two hydrogen bonds form between the two bases. Draw the structure of this base pair. Use bond Any to draw hydrogen bonds. HC H N N R N. NH R H

Draw the structure of the 06methyguanineprotonated cytosine base pair (three hydrogen bonds form between the two bases). Use bond Any to draw hydrogen bonds. CH3 N N R N R N. H

Equilibrium is established between ice and water at 0C. An experiment has been conducted to disturb the equilibrium by increasing the pressure from 1 bar to 5 bar, If the density of water at this condition is p 0.999 g cm and for the ice p 0.917 o cm calculate the change in chemical potential for liquid water. (1 bar 105 pa) 04.97mol A80 ymol 7.21

Ibuprofen is used as an analgesic for the relef of pain, and also to help reduce fever. What is the hybridization state of carbon indicated by the the structure of ibuprofen shown below CH3 CH HC HC CH2 H. HC O sp O spa sp sp spd

Determina el AG rx de la siguiente reaccin usando el conjunto de reacciones en listadas CaCO3() CaO(s) CO2 (g) Ca(s) CO2(g) 02(g) 2 Ca(s) O2(g) CACO3(s) AGn734.4 kJ rxn 2 CaO(s) AGn 1206.6 kJ 3D rxm Seleccione una O a. 200.4 kJ O b. 320.3 kJ O c.472.2 kJ O d. 124.9 kJ

External pressure of 30 bar is exerted on a volume of liquid water at 27c. Calculate the percent increase in vapor pressure as a result of this. The molar volume of water at this temperature is 18.1 cm mol, 1 bar 10 pa. 2.18 0.00731 00731 7.31

11) Provide the mechanism for the following reaction. H Me 2 Li, NH, then Quench Me

Can somebody draw the mechanism for preparation of aryloxyacetic acid from cresol? for p, m, and o-cresol?

Draw two different routes (starting materials) to the following ether using the Williamson ether synthesis. Indicate the preferred route if there is one.

Calculate the equilibrium constant of the following reaction at 25C from standard potential data 2Hg(1) Cl2(g) Hg2Cl(s) 9.59 x 1054 3.10 x 1027 1.41 x 1017 7.18 x 1036 2.70 x 1018

A student identified an organic unknown based on the IR spectrum as an aliphatic carboxylic acid. Explain what signal on a mass spectrum will also confirm that the unknown organic compound is a carboxylic acid.

Discuss the relationship between Compounds A, B and C. Then draw a diagram to show what you would expect to see on a TLC plate if you compared the three compounds on the same plate. OH OH 1 1 1 OH Compound A Compound B Compound C

The book describes the polymerase chain reaction. A) If one of the primers has a point mutation distinct from the template what is the percentage of double stranded DNA that contains a single point mutation after 3 PCR cycles (meltannealpolymerize) B) Illustrate where you would place primers, and in what orientation, to amplify circular

Determine what point group does PF 5 belong to, discuss how that point group is constructed, and discuss where do the linear and quadratic terms of that point group come from.

What are some differences between X-ray diffraction data from small molecules versus macromolecules?

share a favorite recipe for baking a turkey for thanksgiving little bit of research to tell us what is happening at the molecular level in this recipe write all the chemical and physical change in the food from the beginning to end

Given the information below for the molecule azulene, what is the electron density of C5 in azulene NOTE Give your answer to 3 decimal places. Filled Energy Levels (i) (v) of arulene a231B a1.65B a1.368 a0.898 a0.488 0.323 0.268 0.221 0.259 0.543 0.280 0.324 0.000 0.583 0.000 0.323 0.268 0.221 0.259 0,543 0.289 0.191 0.484 0.219 0. 160 Atomie

N2(g) 202(g) 2NO2(g) Use the standard thermodynamic data in the tables linked above. Calculate Delta G for this reaction at 298.15K if the pressure of NO2(g) is reduced to 15.28 mm Hg, while the pressures of N2(g) and O2(g) remain at 1 atm. Standard enthalpies NO2(g) 51.3 202(g) 0 N2(g) 0 ANSWER kJmol

1. Your Blood Ph Is Slightly Alkaline. Its PH Is Always 7.4. You Would Be Very II If Your Blood PH Is Higher Than 7.6 Or Lower Than 7.2. The PH of Your Urine Changes To Help Adjust The Blood PH. If your blood gets too acidic, extra acids comes out in your urine. your urine ph gets lower If your blood gets too alkaline, extra alkli comes out in

What substrate is used in the ELISA simulation and what color is visible in a positive result A. ABST and yellow B. TMB and blue C. TBST and colorless D. ITGP and blue

How does horseradish peroxidase (HRP) contribute to creating the final colored sample A. HRP is a protein that becomes colored when bound to an antibody associated with its epitope. B. HRP is an enzyme that catalyzes the conversion of a substrate to a colored product. C. HRP is a type of antibody that changes color when incubated overnight with

For chemical thermodynamic reasons that have nothing to do with biological issues, only certain energy source=TEA reactions can be used to obtain energy. Which of the following energy source-TEA combinations is NOT used by any prokaryote to obtain energy? A. Molecular hydrogen-carbon dioxide B. Ferric iron-nitrate C. Hydrogen sulfide- molecular

3. What information is missing from the following Table of catalytic results (they defined the ligands used elsewhere in the paper). How many turnovers are they doing Table 1 Asymmetric hydrogenation of methyl aacetamido cinnamate Entry 1234567 3 4 5 6 Ph 7 NHAC 2a Ligand 1a 1b 1c 1d le 1f 1g OMe H Solvent Conv. toluene 100 toluene 100 toluene 100

?A solution was prepared by mixing 25.00 mL of 0.080 0 M aniline, 25.00 mL of 0.060 0 M sulfanilic acid, and 1.00 mL of 1.23 x10 -4 M HIn and then diluting to 100.0 mL. (HIn stands for protonated indicator.) The absorbance measured at 550 nm in a 5.00-cm cell was 0.110. Find the concentrations of HIn and In- and pKa for HIn.

O NH, Anilinium ion PK 4.601 HIn 325 2.45 x 104 M cm1 Esso 2.26 x 10 M cm 1 OS NH Sulfanilic acid pK 3.232 H In 1 325 4.39 x 10 M cm1 1.53 x 104 M cm 1 Esso

Draw the mechanism for the solvolysis reaction of t-butyl bromide in isopropanol The dielectric constant of isopropanol is 18, will the solvolysis reaction in ethanol of this substrate be slower or faster compared to isopropanol. Briefly justify your answer?

What is the product expected trom the following reaction CH, NeCN NaCN CH

How would you make this compound. Please provide what each compound would look like after each step

H 0 L

After softening, water is known to have a buffer of 93 mg/L as CaCO3, and a pH of 9.6. How many millimoles (mmol) of hydrogen ion need to be added (per litre) to bring the pH down to 9?

A central atom with sp2 hybridization has a(n) electron group geometry. O bent R O linear O trigonal planar trigonal bipyramidal tetrahedral

How adding a 0.2 mM of myelin basic protein to the aqueous solution will alter the lipid phases in ternary phase diagram of POPC/SM/Cholesterol?

Digested sludge has a molar concentration of 0.005, 0.1, and 0.004 for Magnesium, Ammonia, and Phosphate, respectively. What volume of water should be added to each unit volume of sludge to prevent struvite precipitation, assuming that at this pH the solubility pks is 6.8

(b) With the aid of simplified molecular orbital energy level diagrams, explain why the 18electron rule applies to metal complexes of all coordination numbers and not just six coordinate complexes.

what is the product of the reaction of concentrated ammonia and ammonium carbonate? NH3 + (NH4)2CO3=? to the product of the above reaction then slowly added to an aqueous solution of CoSO4H2O.(Cobalt sulfate) Initially, a precipitate formed? What would be the precipitate? It was not CuSO4.The question is asking about the CoSO4 An aqueous solution

The chief component of eucalyptus oil is X, which contains 77.87 C, 11.76 H and the reminder O. (C 12.0107 gmol, H 1.00794 gmol, O 15.9994 gmol) What is the empirical formula of X C3H9O2 A CioH30 B CSH3O C10H180 E

3. For each of the following reactions, draw the arrowpushing mechanism that leads to the product shown. Use your knowledge of pKas to determine if the reaction shown is likely to happen, and briefly explain your rationale. In the cases where the reaction drawn is not likely, draw the mechanism of the correct reaction. OH a) HO O Lit b) OH HO

To improve chemical resistance and working properties of sodalimesilica glass, ALOs is often added to the glass by adding soda feldspar (albite), Na(AISis)Os, to the batch formula. Calculate the formula of the glass produced when 2000 kg of the batch formula is supplemented with 100 kg of this feldspar.

Suppose we have an economy which lasts only for one period. There are N individuals of each of two types. There is a single good produced (coconuts). There is no money. Because of these assumptions, there will be no trade in the goods market. (And there will be no credit market whatsoever.) This is essentially a big, Nperson Robinson Crusoe

Propose the arrowpushing mechanism for the product of the dehydration reaction. OH H,SO, heal

What is the mass spectra for potassium trioxalatoferrate( III ) trihydrate?n

Using the thermodynamics values from the provided table, determine the standard enthalpy change for the reaction Zn(s) Cu2 (aq) Zn2(aq) Cu(s) Express your answer in klmol to one decimal place. Do not include units. QUESTION 9 Calculate the free energy change for the reaction in the previous two questions. Express your answer in klimol to one

Using the thermodynamics values from the provided table, determine the standard enthalpy change for the reaction Zn(s) Cu2 (aq) Zn2(aq) Cu(s) Express your answer in kmol to one decimal place. Do not include units.

How would you achieve the following transformation

3. Often thermodynamics and kinetics are collectively referred to as reaction energetics in chemistry. How do thermodynamics and kinetics differ How are they similar to one another Use 3 example problems from 3 different chapters, worked out with correct answers, to support your position.

Write stablity order of following intermediates (b) (c) (d) (a) HC (b) CH, CH (e) , , (0) HCc (b) CH, (c) CH, CH,

The solubility of mgc2so4 in water is 0.093. find kps

Draw the DielsAlder product (a) maleic anhydride heat (b) maleic anhydride heat H,C. CH3 (c) maleic anhydride 250 C

Define a chemical bond. Name various types of chemical bonds. How Valence Bond (VB) theory explains chemical bonding?

2.2. Calculate K for the following reaction given the following equilibrium concentrations of Hz. Co, and HO. 2.3. When 3.00 mol of A and 4.00 mol of B are placed in a container and allowed to come to equilibrium, the resulting mixture is found to contain 0.80 mol of D. What is the value of K at equilibrium A(g) 2B (g) C (g) D(g) K Initial 3.00

A. Find the concentration of salt (lb/gal) in tank 1 and 2 after 100 minutes. B. Find the concentration of salt (lb/gal) in tank 1 and 2 when tank 2 is in full capacity. C. Find the concentration of salt (lb/gal) in tank 1 and 2 when the volume of two tanks are the same. Assumption: No effect of potential energy and friction factor from tank 1 to

1. Two tanks are connected in series. The first tank initially contains 250 grams of salt with 300 L of solution while the second tank contains 200 L of pure water. Assume solutions are mixed thorougly before leaving the tank. Vimax 1000 L, V2mux 750 L. A class number (2 20) 20. (30 pts.) A gL salt 10 Lmin 1 9 Lmin 6 Lmin

a) Explain what is understood by the following terms: (4) i. Octet rules. ii. Ionisation energy.

b) Describe the general arrangement of subatomic particles in the atom.

c) Calculate the average atomic mass of chlorine if its isotopes and percentage abundance are as follows. Show your work. (3) Mass of Isotopes abundance 36.96590 24.47 34.96885 75.53

e) The structure of succinic acid is shown below. HO. OH i. Write down the molecular formula of succinic acid and work out its molar mass. (2) ii. What is the empirical formula of succinic acid (2) iii. What is the percentage of carbon in succinic acid (2) iv. Calculate the amount of succinic acid in a 0.125 g sample of the pure acid. (2) v. How

a) A 1.034 g sample of impure oxalic acid is dissolved in water and an acidbase indicator was added. If the sample requires 34.47 mL of 0.485 M NAOH to reach the equivalence point. i. What is the mass of oxalic acid in the sample (3) ii. What is the mass percent of oxalic acid in the sample (2)

b) Based on the balanced equation 2A B3C AB Ao (molL) Bo (molL) Co (molL) Initial Rate (molL s) 1.00 1.00 1.00 0.120 2.00 1.00 1.00 I 0.480 1.00 2.00 1.00 0.240 1.00 1.00 2.00 0.960 Given that Rate kABC. 3D 3D i. Find the coefficient x. (2) ii. Find the coefficient y. (2) iii. Find the coefficient z. (2) (2) iv. What is the value of the rate

Based on the following information d) A(g) 3Bg) 2Fg) Dg) K 0.0711 3D Ag) Hg) Fg) 2Dg) Eg) F(g) K 0.0401 3Bg) 2Fg) K 0.271 I Calculate K for the overall reaction A (g) Fg) Eg) Ilg) (6)

e) The following reaction takes place at 35 C (3) 2A) B) 2F) 3DR) 2F(g) 3D(8) Ke 0.00785 Calculate K, at 35 C. 17

a) Find the pH of a solution that contains 2.5 moles of hydrochloric acid (HCl) and 1.4 moles of acetic acid (HC HO2) dissolved in 0.11 mL of water. (3) Distinguish between ionization and dissociation. (2) 5 b)

a) Balance the following reaction in acidic medium U0 Cr,03 UO Cr 1. i. Identify the oxidising agent and the reducing agent in the above reaction.

Can you give an experiment that I can do at home about Gravimetric Analysis or Chemical Equilibria?

b) The following chemical reaction is occurring in an electrochemical cell Mg) 2Ag (0.0001M) Mg(0.10 M) 2Ag) The E electrode value are MgMg 2.36 V AgAg 0.81 V Calculate i. the E value for the electrode 2Ag2Ag. (2) ii. Standard cell potential E. (2) iii. Will the above cell reaction be spontaneous Why (2) iv. Cell potential using Nernst

a) Name the three hybridization states and geometries found in organic compounds.

a) Name the three hybridization states and geometries found in organic compounds. (3) b) Draw one structure each of related hybridize carbon mentioned in (a) above and give their respectively names. (6)

c) What is the difference between saturated and unsaturated hydrocarbons Give examples of each. (2)

13 d) Write the functional formula of any four functional groups and give their common names. (2) AVAILABLE MARKS 100

What is the wavelength of the photon emitted by an excited hydrogen atom where m =11 in the Balmer equation?

6. Consider the following information for a galvanic cell:Sn Sn2+ = - 0.14 V and CuCu2+ = + 0.34 Vi. Predict the oxidizing agent and the reducing agent.ii. Write the cell diagram for the redox couples above.iii. Write the half equations for the species above.iv. Write the overall cell equation.v. Draw a fully labelled electrochemical this

A saturated solution of PbI2 has a concentration of 1.65 10-3 mol/dm3 . i. Write the reversible reaction for PbI2 breaking into its constituent ions. ii. Write the equilibrium expression (Ksp). iii. Calculate the concentration of each ion, Pb2+ and I- . iv. Calculate the Ksp.

TWO (2) moles of nitrogen gas and SIX (6) moles of hydrogen gas are mixed and react according to the following equation, N2 + 3H2 2NH3. The reaction mixture was allowed to reach equilibrium at 650 C and 2 x 107 Pa. The mixture contains 3 mol NH3. i. Calculate the number of moles of N2 and H2 at equilibrium. ii. Calculate the partial pressures of

A buffer solution was made up of ammonia and water which produced ammonium ions and hydroxide ions. a. Write the equilibrium equation which represents this buffer and the simplified Ka expression b. Write an equation which shows ammonium breaking into its constituents. Calculate the initial pH and the pKa of this buffer solution knowing that the

Dinitrogen pentoxide (N2O5) decomposes to NO2 and O2 according to the following equation, 2 N2O5(aq) 4 NO2(aq) + O2(g).. Consider the data given below for the following first-order reaction: Time (s) [N2O5] (M) 0 3.6 600 2.7 1200 2.0 1800 1.6 2400 1.2 3000 0.9 3600 0.6 b) Plot a concentration vs. time graph with the following data. c) Write the

Give the Reagents illustrated in the molecules below. For this question, some of the reactions require 2 steps. Make sure to account for all stereochemical outcomes.

Label the following molecules as chiral, achiral, or meso.

airl the following molecules chiral, achiral, or meq Ich)

What is: 1. Capillary Action 2. Adhesion 3.Surface tension 4.pH 5. Boiling point

Directions Identify what property of water is being shown on the pictures elow. 1. 654 2. 3. 71 Dissyi03 no

Directions Answer the following questions briefly but substantially 1. What is cohesion 2. Why do some water insects able to walk on water Explain. 3. Define adhesion. 4. Explain how adhesion and cohesion help plants move materials. ,5. When is water the densest 6. Explain why ice floats. 7. How is a lake or a river that freezes over helpful to

Consider a bacteria community feeding on some fallen leaves. The bacteria has a C:N ratio of 10 while the fallen leaves have a C:N ratio of 50. What nutrient cycling process would happen when bacteria is consuming the leaves? And how much nitrogen would be transformed through the process when 100 grams of leaf carbon is consumed that led to 40

Draw the structure for each iupac name 2-iodo-5-methoxyheptane 3-propyl-1,2-cyclooctanediol 2,2,3,3-tetramethyl-4-decane 1-cyclobutyl-6-isopropyl-2-nonyne

Draw a molecule that contains the characteristics below. LABEL EACH ON YOUR MOLECULE a) secondary alcohol b) epoxide c) sp hybridized carbon d) trigonal pyramidal nitrogen

Draw a molecule that contains the characteristics below. LABEL EACH ON YOUR MOLECULE a) Z alkene b) quaternary carbon c) trigonal planar carbon d) primary alkyl halide

Draw a molecule that contains the characteristics below. LABEL EACH ON YOUR MOLECULE a) R-stereocenter b) tetrahedral carbon c) trans-alkene d) nitrogen with a positive formal charge (+1)

True or false A strong acid completely dissociates into hydrogen ion and a conjugate base A weak acid completely dissociates into hydrogen ion and a conjugate base A strong acid completely dissociates into hydrogen ion and a conjugate acid A weak acid completely dissociates into hydrogen ion and a conjugate acid

Circle all chiral molecules

H,C CH, CH CH3

) Explain why compound A is more acidic than compound B. Be detailed and complete with your response

A B.

Provide a complete arrow pushing mechanism for the reaction shown below

OH

Label each pair as diastereomers, enantiomers, identical, or constitutional isomers.

HO HO HO

A 0.299 g sample of gas was held in a 0.220 L container at 25.0C and its pressures determined to be 0.757 atm. What is the molar mass of the gas?

At 27 C a gas occupies a volume of 600 cm3. What volume does that gas occupy at 227 C, assuming that pressure remains constant? Give the name of the gas law associated with this scenario.

A 2.00 L sample of gas originally at 25 C and pressure of 400 torr is allowed to expand to a volume of 5.00 L. If the final pressure of gas is 585 torr, what is the final temperature in K?

Explain why bond dissociation energy increases as bond order increases.

The standard enthalpy of formation of pentane relates to the equation: C(s) + H2(g) C5H12(l) The standard enthalpy changes of combustion for the three substances in the equation are: C(s) = -394 kJ/mol, H2(g) = -286 kJ/mol and C5H12(l) = -3509 kJ/mol. i. Calculate the standard enthalpy of formation of pentane. ii. State whether the reaction is

Circle the compound with the highest boiling point. Explain your choice

. OH

Draw the LEAST AND MOST STABLE Newman projections for the labeled bond. LABEL all strain interactions present

use this bond for Newman projection H3C CH3