Chemistry Questions and Answers May 27, 2020

Determine which ions are present in cach of the compounds. Cr,0, PbCI, O Pb PbCI Cr O o O C O cr Na, PO, AKCIO,), O CIO O PO O Na AP O CIO, PO, O Al O Na, pi O O O O O D D O O

What is the structure factor of Cu3Au? What is the coordination number of Cu in Cu3Au ?

Describe Cu2O in terms of linked polyhedra.

Propose a synthetic route for the following transformations. If more than one step is necessary, show the product of each step. Do not show mechanism. You may choose to use the reagents from the reagent bank, but not required. Reagent Bank H,0heat MCPBA PBrs Mg HCI SOClz PCC 1. BrzH20 2. NaOH TSCIPyrdine BrMg 1. Hg(OAc) 2. NaBH4 TMSCIPyridine H2Pd

For each transformation in the scheme below, provide the appropriate reagents to carry out the desired reaction.

Each of these reaction produces ONE MAJOR PRODUCT. In each case, draw this product in the box provided, including appropriate stereochemistry when applicable. For multistep reactions, just give the FINAL product, no intermediates. (3 pts each) LIAID. OH 1.PBr 2. NaSH 1. MCPBA 2. H,SO, MEOH Br NaOH 1. DLindlars catalyst 2. Oso, NMO

Synthesize the desired product from the given starting materials. If more than one step is necessary, show the product of each step. Do not show mechanism.

Predict the MAJOR product by proposing a plausible step by step mechanism. Indicate stereochemistry when applicable. H3O Et. OH

This target alcohol can be made from various combinations of organic substrate and reagents. Provide the structures of an alkene, a carbonyl compound, and an epoxide from which this alcohol can be made in one synthetic step, along with the necessary reagents to convert each of these compounds to the alcohol. Alkene Reagents Target Alcohol

What is the expected major product of the following reaction HSO.(aq) So,H SOH D. OB. B O DD OE E

Draw line structures for both

OH OH HO,

Suggest the synthesis of Methyl cyclohexane from molecule A. Give the IUPAC name for molecule A H3C Br H,C CH CH2 CH2 CH3 Molecule A

Do 2 structures of HCN and their formal charge and use FC to choose the best Lewis structure. Draw 5 different structures and their formal charge analysis of N20 and determine the best Lewis structure.

A cup of coffee cools according to Newtons law of cooling (3) In Section 1.3. dT TTm dT k(T Tm) (3) or dt dt Use data from the graph of the temperature T(t) in the figure to estimate the constants T To and k in a model of the form of a firstorder Initialvalue problem dTdt k(T T), T(0) T. TA 200 150 100 50 0. 25 50 75 100 minutes Tm To

A leak allows onehalf of the Ne atoms to escape. Express your answer with the appropriate units. Value Units

A sample of 3.40 moles of Ne is added to the 1.10 moles of Ne gas in the container. Express your answer with the appropriate units. Value Units

A sample of 29.0 g of Ne is added to the 1.10 moles of Ne gas in the container. Express your answer with the appropriate units. Value Units

A gas has composition as given below. Determine a value of zfactor for this gas at reservoir conditions of 5720 psig and 268F. Component Hydrogen sulfide Carbon dioxide Nitrogen Methane Ethane Propane iButane nButane iPentane nPentane Hexanes Heptanes plus Composition, mole percent 20.90 44.69 1.22 21.80 3.68 2.05 0.58 1.09 0.46 0.56 0.72 2.25

1. Given the following termary phase diagram for mixtures of methane, propane and n pentane at 160F and 1500 psia, answer the following questions. a. Will a mixture of 60 methane, 20 propane and 30npentanebe a single of two phase If it is a single phase will it be liquid or gas How did you decide explain. b. A liquid of 80 mole percent propane and

A black oil reservoir has been just discovered. The reservoir pressure is above the bubble point pressure. A flow rate of 88.4 bbld entering the well from the reservoir at the bottomhole was measured. The oil is processed through a two stage separation system that is a separator and a stock tank system. A 56.2 STBD of 44.5 API oil is produced at

A mixture with the total composition given below has a temperature of 160 oF. You are asked to calculate bubble point pressure of this mixture. Use equilibrium ratios read from 5000 psia convergence pressure plots. Comosition mole fraction Component propane nbutane 0.25 0.45 npentane 0.30 1.00

a. 0.7 specific gravity gas will be handled in gas gathering system. Some liquid water is present, At what pressure is hydrate formation is posssible if the temperature is 65F b. If a gaswith a specific gravity of 0.8 (flowing in a conduit containing some liquid water) is expanded through a choke the upstream conditions are 4000 psia and 180 F,

1. Mark all that apply regarding Mastercards competitive positioning. It's a virtual duopoly with Visa makes win-win strategies profitable for both parties. The payment industry has significant barriers for entrants. It has a similar competitive advantage in all markets that it operates. It has strong pricing power.

In the following figure, decide which block is more dense, or it cannot be determined. Explain your answer.

Which one of the following is a chemical change Melting snow Distilling sea water Rusting Iron making tea fro a tea bag

a) Consider the reaction O22 HO 4e 40H Considering the contributions to the flux sketch the concentration gradient of the Oz and OH across the cell when a potential is applied, when the supporting electrolyte is NAOH. b) Repeat for O2 and H in a cell where the electrolyte is HCI where O2 4H 4e 2 H20 (20pts) 3

What volume of 0.2 M AGNO3 is required to react exactly with 120.0 mL of 0.3 M Na SO4 solution Hint You will want to write a balanced reaction. 180mL 90mL O345 ml 360mL O 36mL

Consider the following reaction taking place at 300 K: 2 NH 3 ( g ) + 3 Br 2 ( g ) N 2 ( g ) + 6 HBr ( g ) K c = ?? a) Use the following reactions with known values of K c to determine the value of K c for the above reaction (all values are for reactions taking place at 300 K). N 2 ( g ) + 3H 2 (g) 2 NH 3 ( g ) K c = 4.2 x 10

1. A particular type of electromagnetic radiation has a frequency of 8.11x104 Hz. a) What is the wavelength in meters and in nanometers b) To what region of electromagnetic spectrum would you assign it c) What is the energy (in joules) of one quantum of this radiation (c 3x10 ms h 6.63 x 1034 J.s)

2. What is the maximum number of electrons in an atom that can have the following quantum numbers Label each electron with particular orbital. Consider each cases given below separately a) n 2, m, 12 b) n 4, m, 1 c) n 3, 1 2 d) n 2, 1 0, m, 12

3. Write the Lewis structures for the following compounds and show the formal charges, if any. ) HNO3 b) CN c) N3 d) CIO3 (Atomic numbers H 1, N 7, 0 8, C 6, Cl 17)

4. Calculate the standard enthalphy change (AH) for the following reaction H2(g) I2(g) 2 HI(g) Using (a) bond dissociation energies (HH 436.4 kJmol II 151.0 kJmol HI 298.3 kJmol) (b) standart enthalphy of formations for reactants and products (AH for I2(g) 61.0 kJmol AH, for HI(g) 25.9 kJmol)

(a) A person drinks fours glasses of cold water (3 C) every day. The volume of each glass is 250 mL. How much heat (in kJ) does the body have to supply to raise the temperature of the water to 37 C, the body temperature (b) How much heat would your body lose if you were to ingest 800 g of snow at 0 C to quench thirst (The amount of heat necessary

7. The energy required to ionize sodium is 496 kJ mol. What minimum frequency of light is required to ionize sodium and what is the wavelenght of this light 23 Avogadros number 6.02 x 10 Plancks Constant 6.63 x 1034 J.s Speed of light 8 x 10 msec.

8. SiCl4 used as a starting material in the production of silicon polymers. Describe hybridization schemes for the central atom and the orbital overlap that occur in this halogen compound. ( Si, C1) Data for the arrangement of electron pairs about a central atom in a molecule and geometry of the molecule and the shape of hybrid orbitals Number of

How much heat would your body lose if you were to ingest 800 g of snow at 0 C to quench thirst (The amount of heat necessary to melt snow is 6.01 kJmol). Density of water 1 gmL Specific heat of water 4.184 Jg. C H2O 18.02 gmol

6. a) Consider the reaction N2(8) 3H2(g) 2NH3(g) AHxn 92.6 kJ If 2 moles of N2 reacts with 6 moles of H2 to form NH3, calculate the work done (in joules) against the pressure of 1 atm at 25 C What is AE for this reaction Assume the reaction goes to completion. (1 L.atm 101.3 J R8.314 Jmol. K or R 0.082 L.atm mol.K)

b) Assume that the reaction given above is an reversible reaction. Propose operating condition (temperature and pressure) of the reactor that will give a high yield of ammonia. N2(8) 3H2(g) 2NH3(g) 92.6 kJ

2. What is the maximum number of electrons in an atom that can have the following quantum numbers Label each electron with particular orbital. Consider each cases given below separately a) n 2, m, 12 b) n 4, m, 1 c) n 3, 1 2 d) n 2, 1 0, m, 12

SiCl, is used as a starting material in the production of silicon polymers. Describe hybridization schemes for the central atom and the orbital overlap that occur in this 28 halogen compound. ( Si, C1 ) Data for the arrangement of electron pairs about a central atom in a molecule and geometry of the molecule and the shape of hybrid orbitals Number

The major product for this reaction is NaOH H. heat a. O b. OH d. Od.

1.38 g of NaCl (molar mass 58.44 gmol) as dissolved in 43.3 mL of water. Assuming molar conductivity A ion activity coefficient, a (mSmolcm) Na 50.1 0.699 CI 76.3 0.699 What is the expected conductivity, K, in mScm (If the answer is 30.1 mScm just enter 30.1)

6. A particle moves through a gas at a speed of 15 kms. How far will it move in 5.5 s 7. A solution of barium nitrate contains 61.2 g per litre of solution. How many grams of barium nitrate is contained in 2.75l of this solution 8. Calculate the concentration of 4 KCI solution in i. BL ii. ppm ii. Hgml 9. A soil has 4 ppm P. Calculate the level of

12.Given 1000 cm of a 2 M NH,CI solution N 14gmol, H 1gmol, Cl 35.5gmol, density of H,0 1.00gml i. How much water must be added to bring the concentration to 0.5 M. ii. Determine the percent ammonium (NH,) in the new solution

What is the reducible representation for BH4+

10 Under normal condition, are these compounds (A and B) shown below stable Provide explanation for your answer using a term orbital. Be sure to include Newman projections for your explanation.

Show the re trosynthe tic schemes for the followling. OH

Calculate the concentrations of all species at equilibrium for each of the following original mixtures. a. 3.2 moles of pure NOCI in a 2.0L flask NOCI K 1.5 x 105 for the reaction M 3D NO M 2 NOCI(9) 2 N0(g) Cl2 (9) Cl2 M b. 1.0 mole of NOCI and 1.0 mole of NO in a 1.0L flask NOCI M 3D NO M Cl2 M c. 3.2 mole of NOCI and 1.0 mole of Cl, in

Ribose, a carbohydrate with the formula shown, forms a cyclic hemiacetal, which, in principle, could contain either a fourmembered, fivemembered, or sixmembered ring. To determine which ring is formed, ribose is treated with methanol in the presence of an acid catalyst. The products are then isolated and treated with NaIO4 then with H30. OH MeOH

which hre obes the hydrde ottarth CR) CB cataly THE 25C,3o min

2. Use the data in the handout to calculate AH and AS of the following reactions. From the values of AH and AS, calculate AG at 25 C and predict whether each reaction is spontaneous under standard state conditions. a) Naigi 2 Ozigi 2 NOa

What is the lattice energy of Li3N?

2. Calorimetry A 0.692 gram sample of glucose (Ct206) was burned with excess oxygen in a bomb calorimeter. The calo. er contained 575. grams of water. The initial temperature of the calorimeter and the water was 21.70C. The final temperature of the calorimeter and water was 25.22C. a. Find the AH per 0.692 gram sample of glucose. b. Find the AH

Derive the structure factor for a body centered cubic unit cell of identical atoms. The relative coordinates of the lattice points are given by (0,0,0), (1,0,0), (0,1,0), (0,0,1), (1,1,0), (1,0,1), (0,1,1), (1,1,1) and (12,1,2,12).

Carbon Dioxide has a critical temperature of 304.13 K, critical pressure of 7377.3 kPa and critical volume of 9.41 x 105 m mol 1, By using the Van der Waals Equation of State, calculate the difference between the specific heat capacity at constant pressure and the specific heat capacity at constant volume at the state (293 K 0.45 m kmol1). 252 J

How does changing the temperature affect the equilibrium? How would adding a catalyst affect the equilibrium?

A reaction vessel is charged with 0.50 atm of A and 0.070 atm of B. Once the reaction reaches equilibrium, what is the equilibrium partial pressure of B Kp for this reaction is 67.2 A (g)2 B (g)

Write the equations that represent the first and second ionization steps for telluric acid (H, TeO,) in water. (Use H30 instead of H.) First ionization step H20(1) Second ionization step H20(1)

Write the equations that represent the second and third ionization steps for phosphoric acid (H PO) in water. (Use H30 instead of H.) second ionization step H2O(1) third ionization step H20(1)

The decomponition of HCO,H follows firstorder kinetics HCO,H Coe Hle The halflife for the reaction at 550 Cs 24 seconds. How many seconds are needed for the formic acid concentration to decrease by 337 016

Explain why water will evaporate even at cold temperatures if left in an open container. n

2. How do you compare the pictures 3. Which one is more spontaneous Why ,Coirparn the pictures in cach set Rook roled uphit and downhit. (Image Source osnnolen onimpon 1. What can you say about the pictures 2. How do you compare the pictures 3. Which one is more spontaneous Why 8. Uphil and Downhill Skiing. (Image Source SEYRa CAU 1. What can you

1. A buffer with a pH of 4.49 contains 0.35 M of sodium benzoate and 0.18 M of benzoic acid. What is the concentration of [H3O+] in the solution after the addition of 0.054 mol HCl to a final volume of 1.3 L? Assume that any contribution of HCl to the volume is negligible. 2. What volume of 3.50 M NaOH would be required to increase the pH to 4.93 ?

Directions Classify the given situations below whether the process is spontaneous or nonspontaneous. 1. Rusting of iron in moist air 6. Drying of leaves 2. Decaying of radioisotopes 7 Dissolving of salt 3. Oxidation of gold 8. Radioactive atom splits up 4. Spoilage of food 9. Dissolution of sand in water 5. Burning of chiorine 10. Fireworks

Activity 2. IM EVERYWHERE A spontaneous process is one that takes place without energy from an external source. For a chemical reaction to be spontaneous, it should proceed as written (from left to right), without an input of energy. An endothermic process absorbs heat from the surroundings and has a positive value, whereas an exothermic process

The concentration of a H3AsO3 solution is determined by titrating it with a 0.1483 M solution of Ce4+. The balanced net ionic equation for the reaction is shown below. 2 Ce4+(aq) + H3AsO3(aq)+5 H2O(l)2 Ce3+(aq) + H3AsO4(aq)+2 H3O+(aq) In one experiment, 24.78 mL of the 0.1483 M Ce4+ solution is required to react completely with 20.00 mL of the

Nitric acid can be prepared by bubbling dinitrogen pentoxide into water. N2O5 (g) H2O() 2 H (aq) 2 NO3 (aq) a. How many moles of Ht are obtained when 1.75 L of N205 at 25C and 1.00 atm pressure is bubbled into water mol H b. The solution obtained in part (a) after reaction is complete has a volume of 443 mL. What is the molarity of the nitric

Activity 1. COMPARE ME Compare the pictures in each set. A. shutterst ck Rock rolled uphill and downhill. (Image Source hitpsiencrypted tbn0.gstatic.comimagesgtbn 3AANG9GcRJCzeHyDYohm4N7w Zmeitrausqp3CAU b00whumool 1. What can you say about the pictures 2. How do you compare the pictures 3. Which one is more spontaneous Why

Uphill and Downhil Skiing. (Image Source httosencrypted ton0.gstatic comimacesgton3AANd9QGcS7dY8nkQP2SnYSnusdCUA30S0oJ6Sa6IACdAR USQDDCAU 1. What can you say about the pictures ,2. How do you compare the pictures 3. Which one is more spontaneous Why

6. Digestion of food 7. Boiling water for tea 8. Flow of heat from a cold body to a hot body 9. Diffusion of LPG 10. Making popcorn ,Entropy, S, is the thermodynamic quantity that is a measure of how spread out or dispersed the energy of a system is among the different possible ways that system can contain energy. It is a quantity that is

SUM UP 1. What characterize a spontaneous process 2. How does spontaneity apply to a chemical reaction 3. How do entropy changes occur 4. How is hot object in an open area gets cooler

SOLVE ME 1. Determine S for the reaction SO3g) H20(1) H2SO4(1) Given S(JK.mol) 156.9 256.2 69.9 2. Calcuiate S for the reaction SO2(s) NO2 SO3(g) NO(g) Given S(JK.mol) 248.5 240.5 256.2 210.6 3. Calculate S at 25C for the reduction of a given these absolute entropies 2PBO(s) Given S(JK.mol) 69.54 C(s) 2Pb(s) CO2(g) 5.7 64.89 213.6

Directions Explain how second law of thermodynamics applies in the following. 1. Eating food 2. Hot cup coffee in a table

1. What is the second law of thermodynamics 2. What does second law of thermodynamics telle about the entropy of spontaneous processes and processes at equilibrium 3. When is an entropy change positive or negative 4. Why is the second law of thermodynamics very important to daily life

Activity 1 FIND THE CORRECT NUMBER Directions Assign the correct oxidation number of the individual atom in the compound or ion below. 1. Sin Sa 6. Sin SO42 2. Cl in CaCl2 3. lin 1O3 4. Cin HCO3 5. Sin Fez(SO4)3 7. Sin NazSO4 8. As in KaAs04 9. Crin Cr2O72 10.N in NH4 Activity 2 EXAMINE ME Directions Examine the given chemical reactions and answer

Activity 3 LEOGER Directions Read carefully the given statements, Determine whether oxidation or reduction is described. Write your answer on the space provided. 1. An element changes oxidation number 5 to 2. 2. Oxygen attained oxidation number of 0 from 2. 3. Hydrogen have an initial oxidation of 1 and later had 0 after the reaction. 4. An

Learning Competency The learners would be able to Balance Redox reactions using the change in oxidation number method. (STEMGC11ABIVFg170) Activity 1 INSPECT AND BALANCE Directions Inspect very weli the given chemical reactions and balance the reaction. If the reaction is already balanced, just write the word balance beside the equation. This will

Imagine that a hypothetical life form is discovered on our moon and transported to Earth. On a hot day, this life form begins to sweat, and it is determined that the heat of vaporization of its sweat is 369 calg. The scientist observing the extraterrestrial life form also begins to sweat. The heat of vaporization of the scientists sweat is 580

6. Ammonia can be synthesized according to the reaction Kp 5.3 x 105 725 K N2 (g) 3 H2 (g) 2 NH3 (g) A 200.0L reaction container initially contains a mixture of 13.7 atm N2, 45.8 atm H2, and 0.00 atm NH3 at 725 K. a) Assuming ideal gas behavior, calculate the mass of NH3 (in g) present in the reaction mixture at equilibrium. b) Wil the yield of

The following data were obtained for the reaction 2 ICl ( g ) + H 2 ( g ) I 2 ( g ) + 2 HCl ( g ) Experiment [ICl] 0 (M) [H 2 ] 0 (M) Initial Rate (M/s) 1 0.0015 0.0015 3.7 x 10 -7 2 0.0030 0.0015 7.4 x 10 -7 3 0.0030 0.0045 2.2 x 10 -6 a) What is the initial rate of change of [ICl] in experiment 1? b) What is the rate law for this reaction? c)

3. The reaction N 2 O ( g ) + O ( g ) N 2 ( g ) + O 2 ( g ) has a frequency factor of 3.69 x 10 9 M -1 s -1 and an activation barrier of 67 kJ/mol. Calculate the rate constant for the reaction at 298 K.

4. The decomposition of dinitrogen pentoxide is a first order reaction with a rate constant of 0.15 s -1 at 353K. 2 N 2 O 5 ( g ) 2 N 2 ( g ) + 5 O 2 ( g ) a) What is the half-life of this reaction at this temperature? b) How much time (in seconds) is required for 68% of a sample of N 2 O 5 to decompose?

for this reaction a) What is the rate law for this reaction b) What is the rate constant for this reaction Dont forget units c)A twostep mechanism is proposed for this reaction. Write the chemical equation for the second step. Step 12 NO2 (3) NO3 (g) NO (g) Step 2 d) Which step has the larger activation barrier, step 1 or step 2 Explain your

a) What is the rate law for this reaction b) What is the rate constant for this reaction Dont forget units )A twostep mechanism is proposed for this reaction. Write the chemical equation for the second step. Step 12 NO2 (g) NO, (3) NO (3) Step 2 d) Which step has the larger activation barrier, step 1 or step 2 Explain your answer in 12

Using the mechanism below, what would be the appropriate equilibrium constant expression for the overall reaction Step 1 2 Br (aq) H2O2(aq) 2 H(aq) Br2(aq) 2 H2O(1) Step 2 Br2(aq) H2O,(aq) 2 Br (aq) 2 H (aq) O2(g) Br 02 H,O K HBrH,O, H,O O, K H,O2 0. K 3D H,O, H,OO, 3D H,O,

Using VSEPR theory, determine the electron group geometry and molecular shape of the following substances (a) BF3 (b) NF3 (c) CF4 (d) CF,H2

Explain in words the conversion

HO,HO

Draw a molecular level picture of bromine at 350K and a molecular level picture of bromine at 320K. Show and label any bonds and/or interactions that exist at this temperature. If no bonds or interactions exist, write "none" next to your drawing. n

Which of the following bases exhibit negligible behavior as a base CN NH3 F Br CH3CO2 HSO4 All of the negligible bases listed above are the conjugate bases of choose your answer. . This means that they choose your answer. a strong enough base to take a proton from water. ,Which of the following bases exhibit negligible behavior as a base CN NH3 F

1. Calculate the following (Stote the otomic moss of eoch atom you are using for eoch solution) (a) the percent composition of ammonia, NH, (b) the percent composition af photographic hypo, Na501 (c) the percent of cakium ion in Ca(POdi 2. What is the total mass (amu) of corbon in each of the following molecules (Stote the atomic mass of each atom

5. Compare 1 mole of H, 1 mole af Oz, and 1 mole of Fa. (a) Which has the largest number of molecules Explain why. (b) Which has the greatest mass Explain why. 6. Calculate the molar mass of each of the following (State the atomic mass of each atom you are using for each solution) ta) the anaesthetic halothane, CHBCIF. (b) the herbicide paraquat,

1. Calculate the following (Stote the otomic moss of eoch atom you are using for eoch solution) (a) the percent composition of ammonia, NH, (b) the percent composition af photographic hypo, Na501 (c) the percent of cakium ion in Ca(POdi 2. What is the total mass (amu) of corbon in each of the following molecules (Stote the atomic mass of each atom

8. Determine the mass of each of the following (Stote the atomic mass of eoch atom you are using for each solution) (a) 0.0146 mol KOH (b) 10.2 mol ethane, CH (e) 1.6 K 10 mol Na,SO. (d) 6.854 x 10 mol glucose, CoftOt (e) 2.86 mol Co(NH,luCl 9. A 55kg woman has 7.5 x 10 mol af haemogiobin (molar mass 64,456 gmol) in her blood. How many

For a solution, of HCN, in which u = 0.08: Ka (HCN) = 7.20E-10; calculate the thermodynamic equilibrium constant of HCN?

12. Hydrocarbon mixtures are used as fuels. (State the atomic mass of each atom you are using for each solution) How many grams of CO(g) are produced by the combustion of 200. g of a mixture that is 25.0 CH, and 75.0 Catt, by mass 13. Nitrogen (N), phosphorus (P), and potassium (K) are the main nutrients in plant fertilizers. By industry

4. Determine the molecular mass of the following compounds (Stote the atomic mass of each atom you are using for each solution) ,(February 2021)

Bond-Line Structure For Isomeric Compounds Of C4h8o And Their Iupac Names