Chemistry Questions and Answers May 03, 2020

In the below chemical reaction, list 5 ways to increase the amount of nitrogen gas. 3H 2 (g) + N 2 (g) --> 2NH 3 (g) H rxn = -92.2kJ/mol

List the 3 states of matter in increasing entropy

List two salts that can form a buffer with dimethylamine- (CH 3 ) 2 NH

For which of the following reactions is S > 0. Choose all that apply. 2 H 2 S(g) + 3 O 2 (g) 2 H 2 O(l) + 2 SO 2 (g) 2 CO 2 (g) + N 2 (g) 2 CO(g) + 2 NO(g) NH 4 Cl (s) NH 3 (g) + HCl (g) 2 SO 2 (g) + O 2 (g) 2 SO 3 (g) 2 C 2 H 6 (g) + 7 O 2 (g) 4 CO 2 (g) + 6 H 2 O(g)

Consider the reaction: H 2 CO(g) + O 2 (g) CO 2 (g) + H 2 O(l) Using standard absolute entropies at 298K, calculate the entropy change for the system when 2.14 moles of H 2 CO(g) react at standard conditions. S system = J/K

A solution is made by mixing 150mL of 0.12 M HCN, 100 mL of 0.56 M NaOH and 75 mL of 0.78 M HCl. What is the pH of this solution? The Ka of HCN is 4.0 x 10-10.

When solutions of silver nitrate and magnesium chloride are mixed, silver chloride precipitates out of solution according to the equation 2ANO3(aq) MgCh (aq)2AgCl(s) Mg(NO,)a(aq) Part A What mass of silver chloride can be produced from 1.86 L of a 0.158 M solution of silver nitrate Express your answer with the appropriate units. View Available

You are assigned sample C for this experiment. The sample is composed of calcium chloride dehydrate and potassium oxalate monohydrate. You need to determine the mass percent of each component in this unknown sample. A sample weighing 1.141 g was added to 150 mL of neutral deionized water and stirred for a few minutes. A precipitate of calcium

50weight mullite powder having an average particle size of about 1um was dispersed in water to make a suspension, and then poured into a gypsum mold to prepare a green body. (1) When you want to prepare a sintered mullite body by using the solid state reaction of two powders instead of 1Kg mullite powder, calculate how many g each of the two

We are working toward answering How many moles of sucrose are in 87.34 grams of sucrose ,C12H22011 sucrose (table sugar)

A certain substance A has a boiling point of 78 degrees Celsius and substance B has a boiling point of 110 degrees Celsius. Answer the following questions: a. Which substance has a higher vapour pressure? Why? Explain b. Which substance has a stronger force of attraction? Why? Explain c. Which substance has a higher heat of vaporization? Why?

Guide Questions: 1.What happens to the molecules of water in the container when the temperature increases? 2.Container B shows equilibrium; how does it manifest such balance? ACTIVITY 4: MIND THE GRAPH

Activity 3 PICTURE SHOWS WHAT I KNOW Directions Describe what is happening to the water molecules in the two flaske Biw ono shown in the picture. moiecules water vapors moienules Evaporation No Equilibrium No Escape Yaz, Equilibrium

Suppose 0.22 L of 0.5 mol/L NaOH solution was titrated with 5 L of HCl using phenolphthalein indicator. Calculate the amount of the base and the acid that were used to reach the neutralization point. 0.55 mol of the base and 0.11 mol of the acid 0.55 mol of the base and 0.55 mol of the acid 0.11 mol of the base and 0.55 mol of the acid 0.11 mol of

100 L of 5 mol/L NaOH are required to fully titrate a 50 L solution of HCl. What is the initial concentration of the acid? 10 mol/L 500 mol/L 20 mol/L 250 mol/L

You are an analyst in a hospital laboratory. You receive a urine sample from patients. A crude sample from each is tested for pH and dyed with ponceau and indicates the following approximate concentrations: Patient 1: At least 500 l/mL Patient 2: At least 5 mg/mL Patient 3: At least 2 mg/mL Describe the assay you perform with your

Directions Analyze the problem and answer the questions beit 1. At 50. C the vapor pressure of ethanol is 0.30 atm, acetic acid is 0.08 atm, water is 0.12 atm, and acetone is 0.84 atm. a. Arrange these substances in order of increasing rates of evaporation. b. Arrange these substances in order of increasing boiling point temperature C. Arrange

3. Calculate pH of 0.03 M solution of potassium hydrogen phthalate (KHP). pKi 2.95, pKr5.41

6. Consider the following concentration table. 0(8) 2.0 mol I (initial moles) C (change) E (equilibrium moles) 3 H(g) 4.0 mol 2 NH3(g) 1.0 a) What are the values for each of the vi b) Fill in the concentration table in terms of 5, the extent of reaction. c) According to your concentration table what are the minimum and maximum values that can

4. Malcic acid (HCOCCCOH) has pKai 1.92 and pK2 6.27. At what pH is the COCCCO,H concentration equal to the COCCCO concentration 3D

ZnCl Ph Ni(BF4) EtO Ph A Ph3C. Suggest a reasonable mechanism for the following reaction Ph OCH3 Ph. OCH3 FeCl, Ph Ph OCH3

Consider the cell membrane shown below a. Using the numbers shown (1 or 2). Which part of the lipid bilayer is hydrophilic Which part of the lipid bilayer is hydrophobic (2) b. The blue molecules shown in the figure represent membrane proteins. What type of membrane protein does A represent What type of membrane protein does B represent What type

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCI(aq), as described by the chemical equation MnO,(s) 4 HCI(aq) MnCl, (aq) 2H,O() Cl,(2) How much MnO,(s) should be added to excess HCI(aq) to obtain 335 ml. Cl, (g) at 25 C and 745 Torr mass of MnO,

3. If 0.500 g of cobalt (II) nitrate hexahydrate and 0.500 g sodium glycinate monohydrate in were dissolved in 50.00 mL of water (along with 1 mL of hydrogen peroxide, of course), what would be the absorbance of this solution measured at the Amax

What reaction is occurring Circle one. b) 1. LIAIH. HO O Nucleophilic Substitution Reduction 2. H20 Elimination Oxidation Mechanism

Following the structure of the expected major organic product for each of the following questions specify Stereochemistry clearly, if relevant.

PhS Na product from reaction 1C

what are the bond angles of AsF4Br relative to AsF5? and why? how do the molecule structures differ?

The pH activity profile of lysozyme is shown below. Based on this the optimum pH occurs at 5.2. 100 50 6. 8. 10 pH Lysozyme has two amino acids that influence its activity, Aps52 (pKa4.5) and Glu35 (pKa5.9). Based on the above information, answer the following questions. The percent of the Glu35 yCOOH in the protonated form at pH 5.2 is . O A, 20

3. Draw the mechanism of the following reactions. of 1. xcess MgBr HO, 2. H20 H, H20

3a) Determine what the d manifold looks like for Co2 in a tetrahedral environment if the o SALCS for the ligands are a1, t2, while the t SALCS are e, ti, t2

2. Pyrite (FeS2) can be leached by oxygen in sulfuric acid solution to form ferric sulfate. Write the balanced chemical reaction in ionic and neutral forms and include the phases of the reactants and products.

Proton and 13 NMR of poly(4-methyl-1-pentene) formed under cationic conditions show the presence of five different repeating units. Predict their structure and explain their formation. (G. Ferraris et al., Macromolecules , 10, 188, 1977)

Chemistry How to calculate ELISA results? based on the standards are 1000, 500, 250, 125, 62.5, 31.3, 15.6 ,7.8pg/ML,

Row data A B D E F G H Blank subtracted Standard 1 Standard 2 5 Standard 3 5 Standard 4 Standard 5 3 Standard 6 Standard 7 Standard 8 3 Mean OD Standard 1 5 Standard 2 5 Standard 3 Standard 4 Standard 5 Standard 6 Standard 7 Standard 8 Standard 2.32 1.641 1.0875 0.561 0.3425 0.2425 0.1385 0.108 2.293 1.688 1.132 0.69 0.463 0.348 0.238 0.227 1

What is the fragmentation pattern of the following two compounds? First compound is Beta-(-)-Pinene, and the second compound is Geraniol.

Mass Spectrum 120 93 100 80 41 60 40 09 91 7779 27 20 53 121 29 61 165 136 43 15 forojador 1119 128133 20 40 100 120 140 Relative Intensity

What have you learned about the kinetic molecular model of solids and liquids? What have you enjoyed most about learning the kinetic molecular model of solids and liquids? What do you want to learn more about the kinetic molecular model of solids and liquids?

What have you learned about intermolecular forces? What did you enjoyed most while learning the intermolecular forces? What do you want to learn more about intermolecular forces?

What have you learned about the units, physical quantities, measurement,errors and uncertainties? What did you enjoyed most while learning about the units, physical quantities, measurement,errors and uncertainties? What do you want to know more about units, physical quantities, measurement,errors and uncertainties?

Predict whether ammonium binoxalate would be acidic, basic, or neutral in water. Show all calculations.

Why colour of sky appears to be blue??

The equilibrium constant, K, for the following reaction is 1.20102 at 500 K. PCI5(g) PCl(g) Cl2(g) An equilibrium mixture of the three gases in a 1.00 L flask at 500 K contains 0.295 M PCI5, 5.9510 M PCI3 and 5.9510 M Cl. What will be the concentrations of the three gases once equilibrium has been reestablished, if 4.64x102 mol of PCI3(g) is added

s method uses an adsorption indicator. Select one . Mohr O b. Volhard . Fajan

Which compound are used as indicator in fajans method Select one O a. Flurosine O b. Sodium chloride O c. Axin O d. Sodium bicarbonate

What is the advantage of Mohr method Select one O a. Sample method O b. capability for different PH O c. must be 1M nitric acid solution. O d. very clear colour change

Which method is back titration and should be done in acidic solution Select one O a. Fajans method O b. Mohrs method O c. Volhard method

What is the End point determination in Mohrs Method Select one O a. red color of FeSCN2 O b. brick red color of Ag2CrO4 O c. red color of A9SCN O d. white color of silver chloride

What is the advantage of volhard method Select one O a. very clear colour change O b. must be 1M nitric acid solution. O c. Sample method O d. capability for different PH

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCl(s) Ksp1.8x1010 5.0 ml Volume of AGNO3 is added to the flask. What is pCl Select one O a. 8.15 b. 2.46 O c. 1.44 O d. 3.91

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 10.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one O a. 1.60 O b. 2.63 O c. 1.35 O d. 1.18

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCl(s) Ksp1.8x1010 15.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one . 1.42 b. 2.62 . 1.81 O d. 3.96

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 30.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one O a. 7.02 O b. 8.31 . 3.81 O d. 7.54

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 50.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one O a. 8.58 O b. 8.14 O c. 9.53 O d. 9.35

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 20.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one . 3.39 O b. 1.36 . 2.15 O d. 8.62

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 35.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one . 8.72 b. 8.27 O c. 7.82 O d. 7.28

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 25.0 ml Volume of AGNO3 is added to the flask. What is pCI Select one O a. 4.89 O b. 4.62 O c. 4.36 O d. 3.39

In the titration of 50.0 mL of 0.0500 M NaCI with 0.100 M AGNO3 , the reaction is Ag(aq) Cl(aq) AgCI(s) Ksp1.8x1010 45.0 ml Volume of AgNO3 is added to the flask. What is pCI Select one O a. 8.25 O b. 8.07 O c. 7.46 O d. 9.35

IUPAC name

Consider the combustion of methanol below. If 64 grams of methanol reacts with 160 grams of oxygen, what is the CHANGE in volume at STP. 2CH3OH(g) 3O2(g) 2CO2(g) 4H2O(1) The volume decreases by 45 liters. The volume increases by 45 liters. The volume increases by 22.4 liters. The volume decreases by 67 liters.

Calculate the standard molar enthrall of formation for ethane at 500 C.

(iv) The Ksp for zinc oxide is 3.5 x 1017. What concentration of zinc sulfate (in molL) must be dissolved in water in contact with solid zinc oxide to obtain a solution pH of 5.9.

Question 6 For 0.4847 M KNO, what is the pH of a 3.367e2 solution of acetic acid Again, using the two alternate definitions of pH. For the concentration definition of pH you should ignore activity (i.e., solve in the usual way). You can assume because the KNO3 concentration is high that it determines the ionic strength, i.e. you can assume that

13. A Beers law plot for K2Cr207 was experimentally obtained. Which graph represents a correct Beers law plot Conc Conc Conc Conc Submit Answer Tries 02 Abs Abs

Calculate the amount of ammonium in grams that is required per electron equivalent of dichloromethane (CH2Cl2) in wastewater when subjected to aerobic biological treatment if fs = 0.35. Assume there is sufficient oxygen present, CH2Cl2 serves as both an electron donor and carbon source, and ammonia is nitrogen source. Hint: For the cell synthesis

I have a question about Atomic absorption spectroscopy. Which method is better internal standard method or calibration curve method, when quantifying the iron component in stainless steel? and please tell me the reason

Let A, B, C be three points in 3D, and consider the the ray p0 + t * r. (1) find the intersection point of this ray (2) find the plane containing these points.

Match the six molecules with their corresponding IR. NH2 OH OH A C D E F LOD 4D00 3000 2000 1S00 1000 S00 RAVENUMB ERIl

Outline a procedure you would follow to identify either an unknown compound OR an unknown acid OR unknown base. Be sure to follow scientific method in your work. Explain whether using solid base pellets rather than aqueous base (e.g. sodium hydroxide pellets rather than aqueous sodium hydroxide) would alter the enthalpy found in activity 3 and if

Determine the molarity of each of the ions present in the following aqueous salt solutions fassune 100 ionization) (a) 6.29 MCuBr lons O Br OBr O Cu D Cu O Br, cation) anion

From the list provided, choose the reastion conditions that will bring about the overall transformation shown below OA CH3CH2OH, H2504 (cat.) OB (1) Mg. ether (2) 2methyloxirane (3) H30 Oc MCPBA OD (1) LIAIH4, ether (2) H30 OE (1) CH3NH2, pH 5 (2) NABH3CN O ) PPh3 (2) Buli (3) benzaldehyde Oa(1) PPH3 (2) uL (3) acetophenone OK() Mg, ether (2)

Some of these projections are of the same molecule. Some are a different molecule. Please select all conformers that are of the same molecule. There is only one molecule represented by two or more projections. OMe H. H OMe H A C D O O O O

Red gold is a goldcopper alloy used to make jewelry. A piece of jewelry made of red gold weighs 9.05 g and has a volume of 0.561 cm. Gold has a density of 19.3 gcm and copper has a density of 8.96 gcm. Calculate the percentage by mass of each metal in the jewelry. Assume the total volume of the jewelry is the sum of the volumes of the two metals

From the list provided, choose the reaction conditions that will bring about the overall transformation shown below CHCH,Br OA H2NNH2, pH 5 Oa ) Mg ether (2) 2methyloxirane (3) H30 OC(1LIAIH, ether, (2) Hyo OD. (CHalNH, pH S O ()CH3NH2, pH 5 (2) NaaCN OK H2NNH2. KOH, heat

Predict what the HNMR spectrum of the following compound will look like, in terms of the approximate chemical shift of the signals of each of the groups of protons in the molecule, their splitting (multiplicity) and their relative areas (number of hydrogens) a N f d

Predict the reagents for the following transformation Me. Me. B. C 1. KH, 18c6 THF 2. 1. NaOMe, MeOH 1. NaOMe, MEOH 1. LDA, THF 2. 1. NaOMe, MeOH H. H 2. NaOMe, MeOH heat 3. PCC, CH,Cl 2. NaOMe, MeOH heat 3. MCPBA, CH,Cl2 3. NH,CI (aq) 4. PCC, CH,Cl 2. H,O 3. NH,CI (aq) 4. PCC, CH,C 020 3.8 D.

Which of the following particles would NOT have the groundstate electron configuration indicated below 1s2 2s2 2p6 3s2 3p6 4s 3d10 4p6 Kr Rb Se2 Br O z2

Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO,. Dissolved CO, satisfies the equilibrium equation co,(g) Co, (aq) K 0.032 The acid dissociation constants listed in most standard reference texts for carbonic acid actually apply to dissolved CO,. For a Co, partial pressure of 6.8 x 10 bar in the

2. A child weighing 14.5 Kg is to get 10 mgKg of Tylenol. The Tylenol is available as 160 mgS mL. How many ml should this infant receive

A cylinder of oxygen has a volume of 2.25 L. The pressure in the cylinder is 1470 pounds per square inch (psi) at 20 C. What volume will the oxygen occupy at standard atmospheric pressure (14.7 psi) assuming no temperature change

What is the best choice of reagent(s) to perform the following transformation

Two elements, Pumpkinium (Pm) and Candium (Cn) combine to form several Compounds including Pm2Cn3 & Pm2Cn5. A 254 g sample of Pm2Cn3 has 6.77 10 24 atoms total. Find the relative mass of Pm to Cn in Pm2Cn3 when you have 45.6 g Pm & 23.1 g Cn

HHeH2 is a linear trinuclear ion with the He occupying the central position, and the two hydrogens occupying the terminal positions. Build a reasonable qualitative molecular orbital diagram for this ion. The relative energies for the 1s orbitals of H and He are as follows 1s(H) 13.61eV 1s(He) 24.59 eV.

2. For each of the above reactions, indicate the mechanism. (SN1, SN2, E1, E2), 3. Show the mechanism (all electron arrows and all intermediates) for the following reaction CHCH,OH heat Br

Which of the following samples has a larger mass O 19.3 g of Au 8.92 10 atoms of Pt Identify the molecular geometry around the three selected atoms. Treat that atoms as the central atom for each part. H H H EN Molecular Geometry at A I Select ) Molecular Geometry at B I Select ) Molecular Geometry at C I Select )

Provide a complete synthesis, choosing all necessary reagents from structures below. ONa OH

what is the empircil formula of C22H44?

1. there are ------mole of bromide ions in 0.500L of a 0.300M solution of aluminum bromide(AlBr3) 0.500 0.150 0.450 0.167

Part A Complete the following reaction. H, H,0

Write down the total Hamiltonian for LiH 12 Well label the relevant variables.

Balance this equation _____ Na2CO3 + _____ CaCl2 -----> _____ CaCO3 + ____NaCl this is what I got: _____ Na2CO3 + _____ CaCl2 ----> CaCO3 + 2 NaCl is this correct?

A 27.9 mL sample of 0.306 M trimethylamine, (CH,),N, is titrated with 0.214 M nitric acid. After adding 14.4 mL of nitric acid, the pH is

You have a compound that has an elemental analysis that goes with the formula K 2 TaF 7 . You certainly would be able to tell the structure by single crystal X-ray crystallography, but what you have available is only F-19 NMR in solution. Would you be able to differentiate the three different geometries for coordination number 7 (assume they are

Calculate the volume, in liters, of 1.599 M KOH that must NH3 CI be added to a 0.104 L solution containing 10.47 g of glutamic acid hydrochloride (H, GluCl, , CH, HO MW 183.59 gmol) to achieve a pH of 10.33. Glutamic acid (Glu) is an amino acid with pKa values of pKal 2.23, C0 pKa2 4.42, and pKa3 9.95. volume L Glutamic Acid Hydrochloride

Which SN2 reaction is each pair is faster OBr O. OOCH3 Br A. OBr Br OCH3