Chemistry Questions and Answers April 28, 2020

Km and Vmax obtained from the Lineweaver Burk plot and linear regression analysis for the data in Table 2 are 16.9 mM and 503 mM respectively. Compare these values to the values obtained Vmax 525.3 Msec Km 20.70 M . Which method, nonlinear regression or linear regression, is more tolerant to an experimental error Note that lower substrate

5. Carbamoyl phosphate (shown below) is an intermediate in the biosynthesis of urea. Based on the discussion of highenergy phosphates, would you expect carbamoyl phosphate to possess a high free energy of hydrolysis Provide a chemical rationale for your answer (Draw structures of product(s) and relevant resonance structures) H2N

Write the schematic representation and reaction of the cell composed of SHE and cadmium electrode. Deduce the half-reaction potential of the cadmium electrode from the E cell = - 0.403 V. Is the reaction spontaneous or not? Why or why not? If it is not spontaneous, how should the schematic representation be written to make it spontaneous?

1) Which of the following are principles on which to base column chromatography? A) Molecular size B) lon exchange C) All of these D)pl E) Both molecular size and ion exchange 2) The use of SDS in protein samples for analysis by polyacrylamide gel electrophoresis will: A) Denature proteins AND impart a negative charge B) Keep proteins in a native

When electrophoretic separations are done based on molecular weight, the distance that a molecule moves can be graphed as a straight line when compared to None of these O the negative of the molecular weight of the proteins the log of the molecular weight of the proteins O The molecular weight of the proteins O MW 2 ,In the active site of

Question1) When we have more s-character, the stability decreases. Could you please tell me the reason, please? Question 2) sp3-s vs sp3-sp3. Why sp3-s has more s-character than sp3-s? Could you please tell me the reason?

What would be the advantages of using a qualitative instead of a quantitative analysis? What are the limitations? Is solubility a qualitative or quantitative laboratory technique? Explain your answer.

A stirred-tank fermentation reactor has height 2 m, diameter 1.5 m, and is filled with a fermen- tation broth that can be assumed to have the physical properties of water. The fermenter must be must be maintained at a temperature less than 42 C to prevent damage to the cell culture. After allowing for sensible heat losses to the cold feed, the

A glass vessel contains 16.0 g of CH 4 gas. Assuming ideal gas behavior, what would happen to the pressure exerted on the walls of the vessel if 2.0 g of hydrogen gas were added to the vessel? The pressure would: A increase by 50% B quadruple C triple D double E increase by over 500%

5. Calculate the pH of a 0.350 M CH3NH2 solution. The Kb for this weak base is 4.4 x 104.

5. Consider the titration of a 25.0 mL sample of 0.100 M in NH3 (Kb = 4.4 10-4) with 0.100 M HCl. a) Calculate the pH after adding 5.00 mL of the titrant. b) Calculate the pH at the equivalence point.

A solution is made by mixing 250.0 g of hexane and 50.0 g of octanol. What is the mass percent of the octanol?

A 0.664g sample of glucose, C6H12 O6, was burned in a constantvolume calorimeter. The temperature rose from 22.30 C to 26.00 C. The calorimeter contained 519 g of water, and the bomb had a heat capacity of 620. JK. What is AU per mole of glucose AU kJmol C6 H12O6 3D

4. Which of the following reacts fastest by an Syl mechanism a. CHCH,Br b. (CH,),r . ,Br d. Br

5. What can we say about carbocations a. They have an sp3 hybridized carbon atom. b. They behave as Lewis bases. c. They have a trigonal planar geometry. d. They form as intermediates in S 2 reactions.

Write the Quotient (Keq) of the reaction for high ionic strength water (activity coefficients needed). Label the terms of the equation. how to calculate the activity coefficients. 2KAlSi 3 O 8 (s) + 2H + (aq) + H 2 O Al 2 Si 2 O 5 (OH) 4 (s) +2 K + (aq) + 4SiO 2 (s)

How many proton signals will there be for 1 chloro3methylbutane CI Group of answer choices 4

An incompressible liquid at 4.0 bar boils at 70 K. Use the chemical potential to calculate the molar volume of the liquid. Express your answer using two significant figures.

The instruction booklet for your pressure cooker indicates that its highest setting is 12.2 psi . You know that standard atmospheric pressure is 14.7 psi, so the booklet must mean 12.2 psi above atmospheric pressure. At what temperature in degrees Celsius will your food cook in this pressure cooker set on high Express your answer numerically in

If humans used RNA instead of DNA, how would it affect the formation of chromosomes? Also, what do you think will happen to chromosomal structure if the nucleic acids were dideoxy nucleic acids?

1) I want all possible stereoisomers of the following reaction and also the intermediates of each stereoisomers. 2) major product of this reaction is endo, and how can I get Exo.

A sample of groundwater taken from a well contains Calcium (Ca 2+ ) = 80 mg/L and Magnesium (Mg 2+ ) =24 mg/L. What are the concentration of both expressed in mg CaCO 3 /L and meq/L?

An element X forms both a trifluoride, XF, and a pentafluoride, XF,. When 6.000 g of XF, are converted into the pentafluoride, 7.728 g of XF, are obtained. What is the identity of the element X

How many milliliters of ethanol are in 500.0 mL of 40.0 % (v/v) ethanol?

How much 0.573 M KOH will be needed to raise the pH of 0.215 L of 3.23 M carbonic acid (H2CO3) to a pH of 9.863

A solution contains 5.8010 -3 M barium nitrate and 1.2710 -2 M silver acetate .Solid ammonium chromate is added slowly to this mixture. What is the concentration of barium ion when silver ion begins to precipitate? [ Ba 2+ ] = M

A disinfection tank is 52m For a free chlorine concentration of 1.2mgL, what is the maximum fiow that this tank can process whilst still achieving a 3log inactivation of giardia cysts at 10C You can assume the water has a pH of 7.0. a. 18Ls b. 8Ls C 10Ls d. 7Ls

. The rate constant for the decomposition of a 0.300 M gas was studied at three temperatures. a) Complete the table below by providing the data needed to obtain the activation energy by the graphical method. Be sure to label the columns, including any units. (Do not plot the data.) T (K) k (s) 415 4.00 x 10 425 1.46 x 10 435 5.40 x 10 b) Assuming

Joachim arrived onsite to support the project. During the Site Preparation (Activity 8), he found that some cameras views were blocked by building structures which were not shown on the blueprints given to him in the design stage. He decides to revise the camera locations. The Contractor is informed of the changes. He provides feedback that many

1. b) Show the MECHANISM for the POLAR addition of molecular chlorine to cyclopentane. c) The reaction of toluene and ethylbenzene was through the alkyl groups, -CH 3 and -CH 2 CH 3, respectively. Why didnt xylene, which has TWO methyl groups, react with bromine in the time allotted?

The oxidation of Gly3P to 1,3bisphosphoglycerate proceeds with an unfavorable AG which equals 6.3 KJmol, yet the flow through this point in the glycolytic pathway proceeds smoothly. Why

Select below all the catalytic mechanisms used by chymotrypsin to convert substrate into product. A) metal ion catalysis B) covalent catalysis C) acid-base catalysis

(1) (a) Show that for the Schottky two state model, the high temperature limit gives Cy 1T2. (b) Show for the Schottky two state model that Cy approaches zero as T approaches 0 K. Is this relationship consistent with the third law of Thermodynamics Why or why not

A solution of 100.0 mL of 0.0400M sodium propanoate (the sodium salt of propanoic acid) was titrated with 0.0837 M HCI. K of propanoic acid is 1.34 x 105. (Show your work. a. Determine the equivalence volume. b. Determine the initial pH. c. Determine the pH at the equivalence volume. d. Determine the pH after the addition of 50.0 mL of titrant.

18. The reaction of hydrogen and oxygen gases produces 15.0 g of water and releases 48.0 Kcal of neat. How mucn energy is required to decompose 15.0 g of water into nydrogen and oxygen gases IS

16. Steam at 100C passing through a radiator condenses to water and releases heat. If 1500 kcai of heat are released, how much more energy is required to vaporize the water, at 100C, to steam

Calculate the molar solubility of CDCO3 (Ksp 5.2 x 10 12) in 0.025 M Cd(NO3)2 at 25C. Compare this to the molar solubility of CdCO3 in pure water. Explain why the molar solubilities are different (or if they are the same, explain why). 3D

Arrange the following in order of increasing boiling point RbF, CO2, CH3OH, CH3B.. O CO2 CH3OH CH3B RbF O CH3BR CO2 RbF CH3OH O RbF CO2 CH3OH CHBr O CH3B CO2 CH3OH RbF O CO2 CH3B CH3OH RbF

Which of the following statements is true O A neutral Mg atom having electron configuration Ne4s cannot emit photons. O The 1s electrons of a carbon atom shield its 2s electrons better than they shield its 2p electrons. O A neutral oxygen atom in its ground state has two unpaired electrons. O The subshells of the n 4 shell of a chlorine atom are

A 5.00 g cheese sample is analyzed for moisture and ash contents. Using a vacuum oven, the moisture content of this cheese sample is determined to be 45.0%w/w. The dried cheese sample is then placed in a pre-ashed porcelain crucible for dry heating in a muffle furnace. The weight of crucible alone is 25.897 g, while the weight of crucible (with

The microenvironment of the active site can cause an amino acids R group to be protonated at a pH much higher than its pka. True False

56.0 mL of 2.50 M Fe(NO 3 ) 2 is combined with 25.0 mL of 0.0525 M Na 2 CO 3 . K sp of FeCO 3 is 2.1 10 -11 . What mass of FeCO 3 (s) will be produced? in grams What is the [Fe 2+ ] in the solution final solution? in M What is the [CO 3 2- ] in the solution final solution? in M

Explain or describe an experiment that you could do to measure the kinetics of the following reactions (each experiment would need to be different). Be specific about what to measure, how to measure, how to mix, etc. heat a. (NH)CO (aq) 2 H0 (1) 2 NH. (aq) CO (aq) b. The DNAbinding drug proflavin (P) binding to DNA DNA P DNA P

Using the 1H NMR spectra of Dibenzalacetone; deduce the geometry of the C=C bonds & explain if it is Cis or Trans.

What is the energy content, in gigajoules, of a truck diesel tank containing 29.3 gallons of diesel? Use "cetane" for density, molar mass, and heat of combustion.

Briefly describe one way in which scientific research using the tools of computational chemistry can be used to inform strategies to address climate change. Your answer should specify the property calculated, the molecules to be considered, and an explicit consideration of how these results can be used to inform climate change science.

The batch fermentation of glucose to glutamic acid using Brevibacterium divaricatum is described in detail in US patent 2,978,384. In Example I in the patent a 10.5 wt% glucose feed was fermented for 72 hours at 30 C, giving 33.5 wt% glutamic acid yield on glucose. What annual production of glutamic acid can be achieved in a batch fermentation

Can a piperidine structure be written without a Hydrogen attached to Nitrogen? What are the possible structures?

Which of the following pairs would be appropriate to make a buffer of pH 4.0? Group of answer choices a. H 2 CO 3 and NaHCO 3 b. HNO 2 and HNO 3 c. HClO and NaClO d. HCHO 2 and KCHO 2 e.HI and NaI #2 Which of the following will form a buffer? Group of answer choices a. ClO 2 - with slowly added NaOH b. KF with slowly added NaOH c. HClO 4 with

One mole of He is heated from 200c to 400c at a constant pressure of 1 atm. Given that the absolute entropy of He at 200C is 135 J K mole, and assuming that He is a perfect gas. a) calculate delta G, delta H, and delta S for this process b) Delta g comes out negative. What does this mean? explain

The figure shows the solubility of a compound A in three different solvents (IIII) as a function of temperature. Which solvent would you choose to recrystallize A Why Temperature Problem 2 The table below provides the solubility values of an organic compound in three different solvents Solvent at 10C at b.p. of solvent toluene cyclohexane ethyl

Identify 5 molecules that fit the 5 sets of spectra. Indicate any identifying data in each spectrum that supports your result. All mass specs are EI-MS. ( This is just 1 of 5 and there is no additional information like NMR given so please try to solve without it)

There is only 1 type of halogen in this compound. L00 50 4D00 3000 2000 1500 1000 500 KAVENUMB ERI al 100 MSNW0270 (Mass of molecular ion 282) 80 60 40 20 50 100 150 200 250 300 mz TERHSITTTRNCETT Relative Intensity

Explain why they would form this type of band structure (1S 2 2S 1 ), Ga([Ar]3d 10 4s 2 4p 1 )

(1S 2 2S 1 ), Ga([Ar]3d 10 4s 2 4p 1 ), trying to explain why they would form this type of band structure

How many moles of potassium hydroxide would have to be added to 150 mL of a 0.363 M hydrocyanic acid solution, in order to prepare a buffer with a pH of 9.470 moles

5. What is the maximum number of electrons that can occupy any orbital 6. What is the maximum number of electrons that can occupy a porbital 2 7. What is the maximum number of electrons that can occupy the fourth Principal Energy Level 8. Write the noble gas core electon configuration of antimony, Sb.

4. A solution is formed by mixing 400. ml of 1.0 M NH3 and 100. ml of 0.75 M AGNO3. The reaction Ag 2NH3 Ag(NH3)2, K 1.6 x 10, goes essentially to completion. (a) What are the final concentrations of the principal species NH3 Ag(NH3)2 . NO3 (b) Solve the Kr expression to find the small, minor Ag Ag)

How many EPR lines are present in a multiplet arisng trom nypermne couping to the nitrogen nuclei in the radical anion derived from the complex illustrated below and what are their theoretical relative intensities OHO H3C CH3 Ni H3CN CH3 HO 2.

Four trials of 5.00 ml samples of dilute acetic acid solution required 14.8, 18.4, 25.2, and 11.8 mL of 0.250 N NaOH solution for complete neutralization. The density of HC,H3O2 solution was 1.003gml. Calculate the HCH3O2 in the solution. Perform a Qtest to see if all volumes of acetic acid should be retained. What is the standard deviation

During a reversible adiabatic expansion, one mole of an ideal monatomic gas cools by 100 K, and AG is 900 J. R 8.314 JKl mol1. Part A What is the entropy of the final state in J K1 Express your answer using three significant figures. S JK1 Submit Request Answer

A 55.0 L, 2.20 mole sample of air, composed in this case of N2 with molar fraction of 75 and O2 with molar fraction of 25, is separated into its components (by passing it over a liquid nitrogen trap, which condenses the oxygen). The separated N2 and O2 are then each allowed to return to the pressure and temperature of the initial air sample. R

Write the repeating unit of the polymer expected from each reaction

NH2 Sulfuric Eid

Consider the isothermal mixing of two ideal gases of unknown moles and unknown volumes. Which of the statements below are INCONSISTENT with this process? Consider the isothermal mixing of two ideal gases of unknown moles and unknown volumes. Which of the statements below are INCONSISTENT with this process? The entropy of the two gases increases.

Which statement below is most accurate regarding use of Third Law entropy values Third Law entropies are roughly the same for all compounds, since all form crystalline solids near OK. Third Law entropies are just a convenient reference point, much like the standard state. The Debye heat capacity theorem can be used to approximate entropies

Design an air cooler to cool 30,000 kgh of diesel oil from 120C to 50 C. The highest ambient temperature that is exceeded for 40 hyr on average is 40 C. Physical properties of diesel oil over the temperature range of interest can be taken as speci fic heat capacity 2.1 kJkg. C, themal conductivity 0.135 WmC, density 800 kgm, viscosity 1.2 mN ms.

The following two schedules show the amounts of additional satisfaction (marginal utility) that a consumer would get from successive quantities of products A and B. Instructions Enter your answers as whole numbers. MU of Good B Price of B4 MU of Good A Price of A Units of GoodA MUP for A Units of Good B MUP for B 56 32 2. 48 20 32 24 4. 24 4. 20

Indicate the stereochemical configuration for the tetrahedral center in each molecule. You might find it helpful to make a model of each structure to help determine the stereochemistry. H,N a. b. H S S not a configuration center not a configuration center R R

2.1 Which of the folowing best describes a 1 orbital O is a bonding orbital with zero nodes. O R is an antibonding orbital with zero nodes. O H is a bonding orbital with one node. O is an antibonding orbitai with one node. 22 O 4 bonded, 4 nonbonded O7 bonded. 4 nonbonded How many bonded and nonbonded electrons does a molecule with no formal

Calculate the potential of a copper electrode immersed in 0.0440 M Cu(NO 3 ) 2

Which of the following would be the best nucleophile when dissolved in ethanol CI O Br

The number of vacancies in some hypothetical metal increases by a factor of 5 when the temperature is increased from 955C to 1270C. Calculate the energy for vacancy formation (in Jimol assuming that the density of the metal remains the same over this temperature range.

What is the pH of a 0.65M NaClO solution. (Kb=3.448x10^-7)

Choose the correct representation of the ring flip for the following compound OH OH OH OH

The standard enthalpy of combustion of a given substance is 422 kJmol at 25C. At the same temperature, the standard entropy of the same given substance is 123 J(molK). Based on the information given, determine the Gibbs energy of the given substance (in kJmol). Be sure to report your answer to the nearest whole number along with the correct units.

Determine the change in entropy (in JK) when 1.0 mol of gas at 25C and 1.00 bar in a 0.500 L container is compressed to 0.05 L and cooled to 25C. Report your answer to two significant figures and use the appropriate units.

Determine the change in entropy (in JK) when 1.0 mol of gas at 25C and 1.00 bar in a 0.500 L container is compressed to 0.05 L and cooled to 25C. Report your answer to two significant figures and use the appropriate units.

1.5 moles of carbon dioxide initially at 15C and 9 atm is placed in a cylinder with a crosssectional area of 100.0 cm2. It is allowed to expand adiabatically against an external pressure of 1.0 atm until the piston has upwards of 20 cm. Assuming ideal conditions, calculate the change in entropy (in JK) for this process. Answer

The standard enthalpy of combustion of a given substance is 422 kJmol at 25C. At the same temperature, the standard entropy of the same given substance is 123 J(molK). Based on the information given, determine the Gibbs energy of the given substance (in kJmol). Be sure to report your answer to the nearest whole number along with the correct units.

Calculate the water hardness in part-per-million (mg of Mg/L) for a 100.0 mL water sample that is stoic metrically tit rated with 25.0 ml of 0.0250 M ED TA. (At wt Mg 24.0 g)

How much iron ore (that assays at 10.18% Fe) must be used in an analytical procedure that is known to have a low bias of 0.15 g if an overall relative error of 0.48 ppth in the iron content is desired?

What is the density of Cl2 gas [molar mass = 70.90 g/mol] at 34.9C and 1.22 atm?

Provide a full mechanism, using the reagents/reaction conditions in the picture. Use curly arrow notation as appropriate.

HO Me Me NaCIO, 78 11 PMBO 1. Ph3PCHBr NaHMDS, 78 OTBDPS HO 2. TBSOTf 2,6lutidine, 96 PMBO 3. TBAF, ACOH, 77 1. (COCI)2, DMSO, Et3N 2. HSCHCHCHSH BF3OEt 85 (2 steps) Me Me 13 OTBS Me Me S OTBDPS Sml2, PhCHO quant., d.r. 201 Me Me 16 9 OH 1. SO3 py, Et3N DMSO 2. NACIO OTBDPS PMBO PGO OH OPMB 88 (2 steps) PMBO 10 Me Me DIBALH, 95 OTBS tBuLi, HMPA,

Calculate the number average molecular weight M, and the weight average molecular weight M, for a sample of polystyrene with the following composition (where i is the degree of polymerization and the is by weight). Further, calculate the variance of the number distribution of molecular weights (0) and the variance of the weight distribution

Identify the series of reactions that will accomplish the following synthesis. Include all organic, inorganic reagents used, as well as reaction conditions. Write your name on the paper and submit a photo of your answer. ... NCH3

What is the value of Kf for the formation of the ammine M(NH3)2 Assume the concentration of M(NH3)n 0.0020 M The data were graphed giving a straight line plot with an equation of y 5.9484x 9.26. .

If one fluidounce of a cough syrup contains 1.3 grams of sodium citrate, how many grains of sodium citrate are contained in 5 mL Please include one decimal place in your answer Amount of sodium citrate grains

In A Ac kr (Capt Coqts) k1 t (6) Now we define the relaxation time, t, which is the time taken for ACA to decay to 1e of its original value, i.e. at tt, ACA Acae. Concentration, A T Exponential relaxation T Time, t Substituting this condition into the integrated rate equation (6) yields that for this particular reaction mechanism t is related

If 0.800 mol of a nonvolatile nonelectrolyte are dissolved in 3.20 mol of water, what is the vapor pressure PH, o of the resulting solution The vapor pressure of pure water is 23.8 torr at 25 C. Express your answer with the appropriate units.

A solution is composed of 1.10 mol cyclohexane (Pe 97.6 torr) and 2.70 mol acetone (Pa 229.5 torr). What is the total vapor pressure Ptotal above this solution Express your answer with the appropriate units.

What is the partial molar volume of ethanol (in units of mLmol) in a solution with water if 125 mL of ethanol is added to 350. mL of water and the volume increases by only 113 mL Take the density of ethanol to be 0.789 gmL. Express your answer with the appropriate units. V. mi mLmol

Classify each of these soluble solutes as a strong electrolyte, a weak electrolyte, or a nonelectrolyte. Solutes Formula Hydrochloric acid HC1 Potassium hydroxide Formic acid Methyl amine CH3NH2 Sodium bromide NaBr Ethanol C2 H OH Sucrose C12 H22 O11 Drag the appropriate items to their respective bins.

Cyclohexane has a freezing point of 6.50 C and a Kf of 20.0 Cm. What is the freezing point of a solution made by dissolving 0.617 g of biphenyl (C12 H10) in 25.0 g of cyclohexane Express the temperature numerically in degrees Celsius.

Write the net ionic equation for the hydrolysis reaction that occurs when sodium carbonate, Na,CO3 is dissolved in water. Predict if the solution will be acidic, basic or neutral.

N F I. Incorrect number of valence electrons II. Incorrect central atom III. Octet rule not satisfied for at least one atom Given the incorrect Lewis structure above, which option(s) above indicate the error(s). Il only I and III OIll only OThe structure shown is correct Ol and II

a) Propose a synthesis for the phenolic compound below starting from benzene and any compound with 2 or less carbons. CHOCH2CH3 OH

For Li 1-x Mn 2 O 4 , a reversible lithium intercalation-deintercalation reaction occurs in the range of 0 x 1.0. Answer the following questions from this. (a) Represent the charging and discharging processes in a lithium ion battery composed of graphite and LiMn 2 O 4 as two electrodes. Charging process: Discharging process:

When a solution of KMnO4 was left standing in a buret for 3 hr, a brownish ring formed at the surface of the liquid. Write a balanced net-ionic equation to account for this observation.

(2) What if the other H is labelled (H H or DY The reaction will then generate (A) no KIE (B) 1 KIE () al 2I (D) inverse 2 KIE tast CONH .coM slow Explain

Experimental conditions to vary (e.g. pH, temp) for functionalization of caffeic acid and PAH You can add journals books and article Polynlylanne ndhestuo androxideend antobactel OH NH2 COH it cutechol goop OH Caffeio nold Cross tmk bamide

1. Write the formula for cobalt (II) phosphide QUESTION 7 1. Write the formula for silver nitride QUESTION 8 1. Write the formula for lead (IV) carbonate QUESTION 9 1. Write the formula for zinc phosphate QUESTION 10 1. Write the formula for cesium periodate