Chemistry Questions and Answers June 25, 2020

The enthalpy of fusion of mercury is 2.292 kJ/mol and it freezes at 234.3 K under 1 atm pressure. The change in its volume is 0.517 cm 3 /mol upon freezing. At what temperature will the bottom of a 10 m high column of mercury (density 13.6 g/cm 3 ) freeze?

1. Mutation is the driving force of evolution. Explain. 2. Prokaryotes are the reason we have an oxygen rich environment today. Explain.

The internal structure and properties of cells from organisms in different kingdoms are rather different but fundamental macromolecules are highly conserved. Explain

Modify the following example One sample test of approach looks at the infer of an example to a pre-certain cost and checks at a deviation from that cost. For example we'd perceive that the normal starting load for white babies withinside the US is 3,410 grams and need to assess the normal starting load of an example of dark little children to this

DRAW THEIR LEWIS STRUCTURE 5.. 2S04 6. 8 7. 8. CH20 9. CIF3 10. H

The region between the graphs of y and y 3x is rotated around the line a 3. The volume of the resulting solid is

Numbers of values represented How many values can the following 7bit numbers represent (a) unsigned binary (b) twos complement (c) signmagnitude

A function is given. f(x)2x3 (a) Sketch a graph of f. CO NE Solution CA Delate WebAssign Graphing Too Graph Layers Line,(b) Use the graph to find the domain and range of f. (Enter your answers using interval notation.) domain range

What is the impact of climate change on low and middleincome countries, and how are they responding to adapt and increase their resilience

Maria loves eating oats for her breakfast. Her friend Emily who is a chemist, found out that oats contain 0.11 mole arginine, 0.5 histidine and 0.4 lysine. What is the % of arginine in the protein present in oats?

Perform the following mathematical operations and express the result to the correct number of significant figures. 2.526 0.470 80.705 . 3.1 0.623 0.4326 b. (6.404 X 2.91)(18.7 17.1) c. 6.071 X 103 8.2 X 106 0.521 104

1. Give the IUPAC names for the following ethers. a. CH3CCCH2OCH3 . CH3 H, Br b. CICH2CH2OCH3 C. f. Br OCH,CH, OCH3 d. g. CH(CH), CH3 2. Write structural formulas for the following compounds. . 2,3heane b. 2methoxypentan3ol c. cyclohexene oxide

Locate on a Smith Chart the following load impe dances terminating a 500 impedance Tline. (a) Z 200 f2, (b) Z25 (2, (c) Z50j 50, and (d) Z 252000. 2.26 Repeat Problem 2.16 using the Smith Chart. 2.27 A 0.690Along lossless Z, 75 l Tline is terminated in a load Z 15j67 0. Use the Smith Chart to find (a) I. (b) VSWR, (c) Z. and (d) the distance

Consider the following set of data where an experiment was done to determine the molarity of a solute. What mass of sample is needed to reduce the RSD to 0.10 if the sampling constant is 17.3 g Sample Mass Molarity 1 4.8 0.2561 4.9 0.2432 5.1 0.2522 4 4.8 0.2498 5.0 0.2504 Average 4.92 0.2503 St. Dev 0.130 0.00469 The mass that is required would

What is the pH of 2.000g NaHCO3 in 250.00 mL of water

List the factors that determine the resistivity of NaCl solutions.

Calculate the current obtained at a time of 2 s after the application of a potential for the oxidation of Cu to Cu. The concentration of Cu was 5 mM, the diffusion coefficient was 5 x 10 cms and the diameter of the gold disc electrode electrode 1.5 mm. ,Calculate the current obtained at a time of 2 s after the application of a potential for the

25.00mL of Sodium Hydroxide solution was titrated with 23.40mL of 0.5720N Sulphuric Acid. Find the concentration of Sodium Hydroxide in wv.

3.Why is the ionization energy of Ca higher than that of K but lower than that of Mg 4. Consider the following sets of quantum numbers (n, , m, ms). Which ones could not occur For the valid sets, identify the orbital involved. (a) 3, 1, 0, 12 (b) 1, 1, 0, 12 (c) 2, 0, 0, 12 (d) 4, 3, 2, 12 (e) 2, 1, 0, 0 5. Given the following sets of electron

Phosphoryl chloride has the molecular formula of POCI,. (a.) Draw a Lewis structure for the compound following the Octet rule. Calculate the Fc. (b.) A Lewis structure where all the formal charges are zero (octet rule need not be followed). Electronegativity Values CF CI N H SO IC a 1. 4. 3. 3.0 2.1 2.5 3.5 2.5 2.5

7. Consider the following transitions 1. n 5 3 to n 5 1 2. n 5 2 to n 53 3. n 5 4 to n 5 3 4. n 5 3 to n 5 5 (a) For which of the transitions is energy absorbed (b) For which of the transitions is energy emitted (c) Which transitions involve the ground state (d) Which transition absorbs the most energy (e) Which transition emits the most energy 8.

8. A. Below are two different Lewis structures for the thiosulfate ion (S2034). Which is the better Lewis structure based only on formal charge Structure I Structure II . Structure Structure II HoN H 9. There are three possible Lewiss structure of C,H,CI,. (a.) Draw all possible Lewis structures. (b.) Determine which of the structures isare polar

Pb is found in common ores of Pbs, whereas MgSO4 is found in MgSO4- .PbS exists in common Pb ores. Why? explain

Which of the following statements about replication is true O a. During replication in oukaryotes, nucleosomes dissociate and are reformed entirely from newly synthesized histones Ob. Replication proofreading involves 5 to 3 exonuclease activity. Oc Primer removal requires 3 to 5 exonuclease activity. O d.Continuous synthesis is on the lagging

f If you have the experiment set up so that electrons are being emitted from the metal plate, which of the following are true and false True False As long as conditions do not change, all emitted electrons have the same initial kinetic energy. True False The work function for the metal is different for different electrons. True False The energy of

A solution is 0.200 M in Co2+ and 0.0650 M in Cd2+.Calculate the cathode potential needed to lower the Co2+ concentration to 1.00*10^-5 M

1. Construct a schematic diagram based on procedure for the qualitative analysis of commoncations (Co2, Zn2 and Ca2). Focus on how ions are separated and detected by doing various chemical tests. (Sample schematic diagram) Sample Number Reagent 1 Experimental procedure (heating, centrifuge, adjust pH, etc.) Precipitate Supernatant Precipitate

A patient in the ICU has retained secretions. Upon auscultation, you hear coarse rhonchi throughout the lower lung fields. The patient has a strong cough, but their secretions are immobile. What are some airway clearance options you would recommend to assist this patient?

Which of the following ligands will coordinate the strongest to the empty coordination site on the metal complexes shown below. CO, PME3, P(OMe)3, CH3 , F, CF3 a) Mn(CO)s b) ReBr(PME3)4 c) Ni(CH3)(CO)2

Draw four unit cells of the Mg-structure in projection on (0001). Find those symmetry elements which characterise the structure as hexagonal.

QUALITATIVE ANALYSIS ACTIVITY Reports will be written in a clean sheet of paper. 1. Construct a schematic diagram based on procedure for the qualitative analysis of common cations. Focus on how ions are separated and detected by doing various chemical tests. (Sample schematic diagram) Sample Number Reagent 1 Experimental procedure (heating,

Draw the condensed structures of the main product for the following reactions A. Oxidation and Dehydration reactions of alcohol. Structures Oxidation Reaction Dehydration Reaction Alcohol a) propan1ol H2 OH H3C H2 H2 H2 b) butan1ol HO, H3C H2 c) butan2ol CH3 H,C H H2 H2 d) pentan3ol H3C CH3 OH

Show how to synthesis those following compounds. . HO b. NH2 IZ

In a COD determination, 15.00 ml of 0.2500 M K2Cr207 was refluxed with 25.00 ml water sample. After refluxing and cooling, the remaining K2Cr207 was exactly titrated with 24.4 ml 0.5937 M (NH4)2Fe(SO4)2. What is the COD (in mgL) of this water sample

Is there any difference between AT and GC pairs Justify your response.

If 1 mole of Ar has a vibronic transition (ground state to 2nd excited state) at 2290 cm-1 then what is the overall spectral linewidth resulted by the broadening at 2 bar and 300 K.

The cell SCE Ag, Cro,(sat d), Cro, (z M)Ag is used for the determination of pCro,. Calculate pCro, when the cell potential is 0.327 V. E e Ar 0.799 V, K(Ag, Cro,) 1.2 x 10 , EsCR 0.244 V pCro, Submit Answer Try Another Version 3 tem attempts remaining

Count the Primary, Secondary and Tertiary alcohols in these two compound.

CH, Br CH,CHCH,CH,OH 1. CH, CH,CCH, 1. OH Br 3,3dibromo2methylbutan2ol 3methylbutan1ol

Determine the empirical formula of a salt that has 32.38% Na, 22.57% S, and 45.05% O

By analyzing 0.26 g of a nitrogen oxide, 0.079 g of Nitrogen and 0.181 g of Oxygen are obtained. The molar mass of the compound is known to be 92 g / mol. Calculate: a) The percentage composition. b) The empirical and molecular formula.

29.00 g of a Hydrocarbon (formed only by Hydrogen and Carbon) are analyzed by combustion, obtaining 88.00 g of CO2 and 45.00 g of H2O. Find: a) The empirical formula. b) The percentage composition c) If 0.35 moles of the compound equals 20.30 g, determine its molecular formula.

When analyzing 50 g of a compound formed by Carbon, Hydrogen, Oxygen and Nitrogen, 106.02 g of CO2, 27.11 g of water and 8.40 g of N2 are obtained. Determine: a) The empirical formula b) If the molar mass of the compound is 166 g / mol, determine its molecular formula.

Two Iron Sulfides has the following percentage composition: Compound A; 63.57% Fe and 36.43% S, compound B; 53.78% Fe and 46.22% S. Determine the empirical formula for each.

Convert the grams to moles and the following amounts to grams Data: (H2O) = 18 gr / mol; (CO2) = 44 gr / mol; (NH3) = 17 gr / mol. 1. a) 40 g of H2O 2. b) 36 g of CO2 3. c) 120 g of NH3 4. d) 2 moles of H2O 5. e) 3 moles of CO2 6. f) 5 moles of NH3

Determine the oxidation number of the metal for the following compounds: a) NaOH b) Al (OH) 3 c) Cu (OH) 2 d) Fe (OH) 2 e) Ba (OH) 2

Determine the oxidation number of the metal for the following compounds: a) titanium dioxide b) potassium oxide

Calculate the centesimal composition of the following substances a) NH3 b) H2SO4 c) Ca (OH) 2

Balance the following chemical equations and classify what type of chemical reaction do each chemical equation belong. 1. C 02 CO Mg O2 MgO H2O2 H2O O2 CH4 O2 CO2 H2O 5. N2O5 N204 O2 1234.

From 3,750 g of a compound formed by Silver, Carbon and Oxygen, 3,540 g of Silver Chloride and 1,087 g of Carbon Dioxide are obtained. If the compound has a molar mass of 303.7 g / mol, calculate its Molecular Formula.

a. Calculate the mass of NaCl and H20 needed to prepare, at a room temperature of 25C, 1 L of brine having a sa .linity of 150 gL. b. Calculate the volume occupied by the dissolved NaCl.

Question 9. Draw Fischer projections of all the possible stereoisomers for 2,3dibromobutane, label your drawings as A, B, C and D and identify the relationships between molecules as enantiomers, diastereomers, or meso. CH3 H Br Br CH3

Propose a scheme to separate a solid mixture containing methyl 4-aminobenzoate, 1,2,4,5-tetrachlorobenzene, and napthalene. Need to separate 2 of the 3 solids using extraction. show explanation

Write the overall balanced equation for the photochemical monochlorination of propane. Calculate the H 0 for the formation of 2-chloropropane in (1) each propagation step of monochlorination and (2) for the overall reaction.

From the figure below, which substituents occupy the axial positions PPH3 0Re PPH3

What are the rules in naming ethers with halogen Why does CICH2CH2OCH3 named 1chloro2 methoxyethane and not 2methoxychloroethane

7. A sample of oxygen gas has a volume of 545 mL at 35 degree C. The gas is heated to 151 degree C at constant pressure in a container that can contract or expand. What is the final volume of the oxygen gas? A) 750 mL B) 396 mL C) 417 mL D) 267 mL E) 126 mL 8. A 45 mL sample of nitrogen gas is cooled from 135 degree C to 15 degree C in a container

A sample of oxygen gas has a volume of 2.61 L at 21C. What volume will it occupy at 147F if the pressure and number of mol are constant?

Calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from n = 7 to n = 1. energy emitted = _______ J

Determine the oxidation number of THE ELEMENT BOUND TO THE HYDROGEN.: a) PH 3 b) AlH 3 c) AsH 3 d) FeH 3 e) CaH 2

Determine the oxidation number of THE ELEMENT BOUND TO THE OXYGEN. a) Mn2O b) Al2O3 c) CuO d) Fe2O3 e) SeO3

Write a mechanism for the reaction using curved arrows to show electron reorganization. Arrowpushing Instructions CH H3C H An error has been detected in your answer. Check for typos. miscaloulations etc. before submiting your answer

What is another VO2max test protocol besides the Bruce one? Give a description of the protocol and explain which population would it be appropriate for.

Arrange the following molecules in order of increasing average molecular speed H 2 at 454 k, CO 2 at 313 k , CO 2 at 370 k, O 2 at 370 k

A sample of USP-grade citric acid (H 3 C 6 HSO 7 ,three titratable protons) is analyzed by titrating with 0.1087 M NaOH. A 0.2678-g sample requires 38.31 mL of the titrant for titration. What is the normality of the titrant? What is the stoichiometric relationship between the analyte and the titrant? How many moles of the titrant was consumed to

The enthalpy of adsorption of hydrogen gas on the metal surface X is 247 kJ mol. Calculate the residence time of a hydrogen molecule on the metal surface at 420 K. (Assume that To 1.0x10 s). Answer Choices (A) 2.291040 S (B) 1.12x10 s (C) 2.29x104 S (D) 6.30102 S

A solution of HNO3 is standardized by reaction with pure sodium carbonate. 2H Na,CO3 2Na HOCO2 A volume of 23.43 0.06 mL of HNO3 solution was required for complete reaction with 0.9245 0.0008 g of Na2CO3. Find the molarity of the HNO3 and its absolute uncertainty.

1.What is the pH at the equivalence point in the titration of a 15.8 mL sample of a 0.483 M aqueous hydrocyanic acid solution with a 0.372 M aqueous barium hydroxide solution? pH = 2.When a 23.4 mL sample of a 0.425 M aqueous hypochlorous acid solution is titrated with a 0.442 M aqueous potassium hydroxide solution, what is the pH at the midpoint

Compute the root-mean-square speed of H 2 molecules in a sample of hydrogen gas at a temperature of 51C _____m/s

Write the balanced equations for the following reactions: a) iron (III) oxide with nitric acid b) sulfur trioxide with water c) carbon dioxide with potassium hydroxide d) sodium metal burns in an atmosphere of chlorine gas e) lithium reacts with oxygen

Give IUPAC name for each of the following alkyl halides:

CI a) CI b) Br I d) f) Br

A 12.5-mL portion of a base solution of an element from Group 2A is diluted to 500 mL; and the resulting concentration of this solution is determined to be 0.125 M. What is the normality of the original solution?

In the analysis of 0.7011 g of an impure chloride containing sample, 0.9805 g of AgCI (143.35 g/mol) were precipitated. What is the percentage by mass of chloride, CI (35.45 g/mol) in the sample?

Describe all details with chronological facts, that how a newly developed atomic model could overcome the shortcomings of the previous model. Mention all kinds of scientific facts and logical approach, and describe in a systematic manner from the initial atomic model to the last you have studied in the course. Use bullet points and paragraph as

What is the importance of studying electronic configuration in different sector of science Describe in details. Why there are some discrepancies happened in electronic configuration where we can observe the violation of Aufbau principles Describe with examples and logical facts and try to figure out the reasons behind the anomalies. Minimum 500

1. Calculate the number of elements of unsaturation implied by the molecular formula a. C9H12 b. C4H4Cl2 c. C6H8O2 2. Give the IUPAC names of the following alkenes CH3 CHH, CH)2 a. b. CH3 H3 3. Draw the structure of the following alkenes. a. 3methylpent2ene b. hexa2,4diene c. 2,4dibromocyclopentene d. 3bromo2chloropent2ene e. 3ethyl5methyloct3ene

6. Which of the compound would have a higher boiling point (a) cyclohexene or (b) 1,2 dichlorocyclohexene 7. In a given structure of ethynyl estradiol, determine the number of unsaturation. CH OH CCH HO 8. Write the IUPAC name for the following alkynes. a. b. Br CH, Br CH,CHCCCH,CH, CH,CHCCCH, 9. Which of the following compounds, is the most

13. Which alcohol has a higher boiling point a. (i) 2methylpropan2ol or (i) butan2ol b. (i) hexan1ol or (i) 3,3dimethylbutan1ol 14. Predict which member of each pair will be more soluble in water. a. (i) hexan1ol or (i) cyclohexanol b. (i) 3ethylhexan3ol or (i) octan2ol 15. Which of the compound in each pair is more acidic a. (i) 2chloropropan1ol

1. Which of the folowing organic compounds would react to 2,4DNP test Indicate YES or NO on the boxes provided below the structure. (2 pts.) . b. . CH CH3 CHCHCH,CH,CH, (a) (b) (c) 2. Which of the folow organic compounds would react to Schiffs test and Benedicts test Indicate YES or NO on the boxes provided beside the structure. (2 pts.) Schiffs

3. Which of the follow organic compounds would react to Tollens test Indicate YES or NO on the boxes provided beside the stucture. (2 pts.) a. (a) CHCH,CH,COCH b. (b) CHCH,CH,CH,CHO C. (c) CHCHCHCHCHOH d. (d) CHCH2CH2CH,CH(OH)OCH3 . (e) CHCH,CH,CH,CH(OCH3)2 f. HO 4. Predict the product for the following reactions of phenol, aldehydes and ketones.

Predict the product for the following reactions e. CH,. f. OH CH, HjN NO, NO h. H,N NH NO, CH,CHCH CH, NO. i. H,NNH NO, NO, Cu OH COOH k. Cu2 OH

Predict the product for the following reactions Cu OH H m. Ag(NH,), OH n. AgtNH,), OH BrCH,CH,CH INH,), OH

A 250g sample of water at 20.08C is placed in a freezer that is held at a constant temperature of 20.08C. Considering the water as the system, after a few hours, what will be the state of the water a) state of emergency b) solid c) gas d) liquid

A 375g plug of lead is heated and placed into an insulated container filled with 0.500L water. Prior to the immersion of the lead, the water is at 293.15K. After a time, the lead and the water assume the same temperature, 74.93F. The specific heat capacity of lead is 0.127JgC, How hot was the lead before it entered the water a) Need more data b)

At some point, all laboratory chemists learn the same hard lesson Hot glass looks just like cold glass. Rodrigo D. discovered this when he picked up a hot beaker someone left on his bench. At the moment Rodrigo grasped the 413.15K glass beaker, 0.537412 BTU of heat flowed out of the beaker and into his hand. The glass of the beaker has a heat

25.4g of NaOH are dissolved in water within an insulated calorimeter. The heat capacity of the resulting solution is 4.18 x 103JC. The temperature of the water prior to the addition of NaOH was 296.15K. If NaOH releases 44.2 kJmol as it dissolves, what is the final temperature of the solution a) 297.5 F b) 29.7 F c) 29.7 C d) 29.7 K

Carbon dioxide gas can be decomposed into oxygen gas and carbon monoxide 2CO2(g) 02(g) 2C0(g) AH 486 kJ. How much heat is releasedabsorbed when 9.67g of carbon monoxide combine with oxygen to form carbon dioxide a) 6.188146 ft Ibf (foot poundforce) b) 20.052581 kCal c) 20.052581 kcal d) 0.07954 BTU

How much heat must be added to convert 4.77 mol of 268.15K ice into steam a) 2.6x 106 J b) 2.6 J c) 2.60x 102 kJ d) 2.6 kJ

Graph the line y 6 5 4 7 6 5 4 3 2 1 3 2 2 3 4 s 6 7 1 2 3 4 5 6 7

Why is it necessary to study the diffusion of molecules in biological systems?

What is the heat needed to be released so that we can convert 500 mg of steam to ice a) 1.1107686 ft Ibf b) 1506 kcal c) 1.506 J d) 1.427413 BTU

2. Find the general solution for each of the following. Where possible, write your answer as an explicit solution. e. 318 318 618 dy dx dy dx dy dx xy 3y y sin(x) y X 4x 3. (x 1) dy dx y 1 b. d. f. dy dx dy dx dy dx xy 3x 2y 6 h. (2 tan (y) 6x 4 3y2 4y 1) dy 4xy dx

What will be the final temperature of a mixture made from 25.0 g of water at 15.00, 45.0 g of water at 50.00, and 15.0 g of water at 37.0C a) 99.32 F b) 37.4 F c) 99.32 K d) 99.32 C

Given f(x) ln(2 1). Guess a formula for its nthderivative, f(n)(x). (Hint Find f(x), (x), (x), f(4)(x) and so on, until you discover a pattern.)

A coffeecup calorimeter is used to determine the specific heat of a metallic sample. The calorimeter is filled with 50.0 mL of water at 25.0C. A 36.5gram sample of the metallic material is taken from water boiling at 100.0C and placed in the calorimeter. The equilibrium temperature of the water and sample is32.5C. The calorimeter constant is known

Find the distance (d) between the planes 3x 5y 13 and 3x 5y d 17.

Four metals, A, B, C and D were left in a pot of boiling water. After several minutes, all metals were simultaneously put in a slab of wax as seen below. Which of the metals has the highest specific heat capacity ) A b) ) d) D Slab of wax mA mB mc mp