Chemistry Questions and Answers June 01, 2020

The airline American Airlines operates daily flights only within the U.S. However, the administration has decided to start the transcontinental routes shown in Table 1 beginning in January of next year. Route 1 2 3 4 5 6 Table 1. Proposed transcontinental flight routes (round) Estimated demand Route New York London New York Paris Cincinnati

In Ch 9, we found out that certain charged compounds are strong bases that promote elimination, while others are not strong bases but are strong nucleophiles, only promoting substitution. For each of the below compounds, please do the following 1. Label each according to base strength and nucleophile strength. 2. Utilize C.ARIO to support your

Predict the product of the oxidation using KMnO4 of 1-(tert-butyl)-3,5-diisopropylbenzene and create a reagent table for the reaction using 5 grams of the benzene compound. The yield of the product will be 67%. Use the reagents below as a model for what equivalents you would need and what reagents are needed for this reaction aside from the KMnO4

A 250g sample of nickel at 100.0C is placed in 100.0 mL of water at 22.0C. What is the final temperature of the water (Specific heat of nickel 0.444 J(g.C). The density of water is 1.00 gmL)

Balance the following equations. 1. CO2 H20 C,H12O6 O2 2. SiCl H20 H4SIO4 HC1 3. Al HCI AICI, H2 4. Na2COs HC1 NaCl H20 CO2 5. CH6O2 O2 CO2 H2O 6. Fez(SO4)3 KOH K,SO, Fe(OH)3 7. Ca(PO4)2 SiO2 PO10 CaSiO3 8. KC10, KCIO, KCI 9. Al2(SO4)3 Ca(OH)2 Al(OH)3 CaSO4 10. H2SO4 HI H2S I2 H20

The ZnS is a facecentered cubic with sulfur anions and the zinc cations are inside the unit cell. The edge length of the ZnS unit cell is 544.5 pm. Determine the density of ZnS in gcm3 (determine how many atoms are in the cube) (No Units) (Write 2 digits after the decimal)

How much heat (in kJ) is needed to convert 866 g of ice at 8C to steam at 143C (The specific heats of ice, liquid water, and steam are 2.03, 4.18 and 1.99 Jg .C,respectively.). The AHvap of water is 40.79 kJmol. The AHfus of water is 6.01kJmol.

Europium (Eu) crystallizes in a bodycentered cubic lattice. The density of Eu is 5.27 gcm3. Calculate the radius in picometers (pm).

The vapor pressure of benzene (C6H6) is 40.1 mmHg at 7.6C. What is its vapor pressure at 70.8C The molar heat of vaporization of benzene is 31.0 kJmol. (No Units) (Write 1 digits after the decimal)

When X rays of wavelength 1.24 are diffracted by a metallic crystal, the angle of first order diffraction(n 1) is measured to be 17.5. What is the distance(in pm) between the layers of atoms responsible for the diffraction

Balance the following equations. 1. CO2 H,0 C,H2O6 02 2. SiCla H20 H.SIO4 HC1 3. Al HCI AICI3 H2 4. Na COs HCI NaCl H20 CO2 5. CH6O2 02 CO2 H20 6. Fe(SO4)3 KOH K,SO, Fe(OH)3 7. Ca(PO4)2 SiO2 P,O10 CaSiOs 8. KCIO, KCIO, KCI 9. Al2(SO4)3 Ca(OH)2 Al(OH)3 CASO4 10. H2SO4 HI H2S I2 H20

How much barite is required to increase the density of 300 bbls of mud from 4 ppg to 15 ppg. How much 12 ppg mud is needed to prepare exactly 250 bbls of 14 ppg mud What volume of water will be necessary to reduce the density of 1200 bbls of 15.2 ppg mud to 13.5 ppg Calculate how much water and barite must be mixed to make exactly 500 bbl of 14

How much 12 ppg mud is needed to prepare exactly 250 bbls of 14 ppg mud

What volume of water will be necessary to reduce the density of 1200 bbls of 15.2 ppg mud to 13.5 ppg

a) How much barite is required to increase the density of 300 bbls of mud from 4 ppg to 15 ppg.

Calculate how much water and barite must be mixed to make exactly 500 bbl of 14 ppg mud

e) Calculate how much oil, water and barite are required to make exactly 300 bbl of 15 ppg oil mud with 8020 oilwater ratio. f) Calculate how much oil will have to be added to change the oilwater ratio of 100 bbl of 8020 oil mud to 9010. g) If the same 8020 mud is to be changed to 7525 oil water ratio, calculate how much water will have to be

Answer to following questions a) How much barite is required to increase the density of 300 bbls of mud from 4 ppg to 15 ppg. b) How much 12 ppg mud is needed to prepare exactly 250 bbls of 14 ppg mud c) What volume of water will be necessary to reduce the density of 1200 bbls of 15.2 ppg mud to 13.5 ppg d) Calculate how much water and barite must

Briefly discuss why the michaelis-mente equilibrium-assumption cannot be applicable to all enzyme catalysed reactions.

In 1925, Brigg and Halnade reported on the modification of the Michaelis-Menten equation. Briefly discuss the modification and how this improved the Michaelis-Mente equation.

Is there a difference between the dissociation constant (K s ) and the Michaelis constant (K m )? yes or no?

A laboratory rat is exposed to an alpha-radiation source whose activity is 14.3 mCi. a) What is the activity of the radiation in disintegrations per second? b) The rat has a mass of 385 g and is exposed to the radiation for 14.0 s, absorbing 35% of the alpha particles, each having an energy of 9.12 x 10 -13 J. Calculate the absorbed dose in

Identify the two forms of mixed inhibition and briefly describe how the two forms differ.

Briefly describe the effects of a linear noncompetitive inhibitor on the kinetic parameters km and v max and briefly discuss the reasons behind the effect of this type of inhibition on the kinetic parameters.

Propose the synthesis for the following transformations. Other allowed starting material include any inorganic compounds, and any organic molecules containing five (5) carbons or less. Show your work (8 pts. each) NO, (a) . (b) (C) (d) (e)

The chlorination reaction of the following molecule yields one major monochloro product. Cl2 AICI, a. Draw the structure of this product (2 pts.) b. The reaction involves formation of reactive intermediate cations. Draw all the important resonance contributors involved in the reaction mechanism, show your work (4 pts.) c. Compare to an

Suggest a reasonable mechanism for the for the following reaction. H OH

Briefly describe how the effects of a competitive inhibitor can be reversed.

Discuss what half-life means in the context of a single atom vs. in the context of a large sample of atoms.

Discuss Radioactive Decay in detail. Mention its type and describe each term used in radioactive decay. Give an example in real life radioactive decay

A compound has a molecular formula C7H8. The 13C-NMR spectrum of the compound has signals at 50(CFI),85(CH2), and 144(CFI). Om catalytic hydrogenation of the compound, it is converted to C7H12. All structures should be drawn with no bonds between carbon and hydrogen. n

Determine the molecular formula for a compound that shows m/z at 86 and base intensity at 10 and another one that shows m/z at 88 and intensity of the base at 0.04.

The first experimental observation of He2 was reported in 1993 J. Chem. Phys. 98, 3564 (1993). Assuming the well depth is only 8 cm (from dissociation energy measurements) and has essentially a harmonic oscillator form up to the dissociation energy, calculate an upper limit to the force constant k for this intermolecular potential energy curve.

Transitions between energy levels in atoms or molecules depend upon the satisfaction of selection rules. The strength for a transition from an initial state with wavefunction b to a final state with wavefunction f is given by the transition moment integral Ix where u, is the transition moment operator. For rotational and vibrational spectroscopy

Transitions between energy levels in atoms or molecules depend upon the satisfaction of selection rules. The strength for a transition from an initial state with wavefunction b to a final state with wavefunction bf is given by the transition moment integral Ix where . is the transition moment operator. For rotational and vibrational spectroscopy

Constants I Periodic Table When a photon passes through matter, there are three types of lightmatter interactions that can occur Part A 1. Transmission, in which there is no significant interaction between radiation and matter, 2. Absorption, in which the energy and angular momentum of the photon are absorbed by the matter, usually governed by

Vibrational frequencies from instruments are commonly reported in reciprocal centimeters. Based on the values (that you might determine with a FTIR spectrometer), complete the table below for the following diatomic species, which you may approximate as harmonic oscillators. k(Nm1) We (cm1) 130.28 () Molecule 1) Force Constant (Nm) Calculation

Vibrational frequencies from instruments are commonly reported in reciprocal centimeters. Based on the values (that you might determine with a FTIR spectrometer), complete the table below for the following diatomic species, which you may approximate as harmonic oscillators. k(Nm1) We (cm1) 130.28 (amu) ,CO 2143 NO 1876

26.47 CP In the circuit shown in Fig. E26.47 each capacitor initially has a charge of magnitude 3.50 nC on its plates. After the switch S is Figure E26.47 10.0 pF closed, what will be the current in 20.0 25.0 2 the circuit at the instant that the pF capacitors have lost 80.0 of their initial stored energy 15.0 pF

The active ingredient in Antabuse, a drug used for the treatment of chronic alcoholism, is tetraethyl thiuram disulfide, (C2H5)2NCSSCN(C2H5)2 (296.54 g/mol). The sulfur in a 0.4169-g sample of an Antabuse preparation was oxidized to SO2, which was absorbed in H2O2 to give H2SO4. The acid was titrated with 19.25 mL of 0.04216 M base. Calculate the

The picture below shows a model of a chemical reaction. The magnitude of energy associated with each of the bonds indicated in the figure is Bond X 4 eV Bond Y 5 eV Bond A 6 eV Bond B 7 eV If the reaction proceeds in the direction indicated, what will be the change in chemical energy O 2 ev O 11 ev 4 eV 11 eV O 2 ev

A solution containing 4.48 ppm KMnO, had a % transmittance of 30.9% in a 1.00 cm cell at 520 nm. Calculate the molar absorptivity of KMnO, at 520 nm.

A solution containing 4.48 ppm KMnO, had a % transmittance of 30.9% in a 1.00 cm cell at 520 nm. Calculate the molar absorptivity of KMnO, at 520 nm.

Derive the ray intersection pattern for a system suffering from spherical aberration (W404) and defocus (W202). Consider the following cases (a) W202 W40, (b) W20W40 (c) W202 W40, (d) W20 0. In all cases, plot the size of the intersection pattern as a function of r, wherer varies from 0 to 1, and thus justify why case (c) is the best geometrical

In a chromatographic column, the concentration of a solute is expressed as the following. V4rDt where c is the concentration, m is moles per unit crosssectional area, D is the diffusion coefficient of solute, x is the distance along the column from the current center of the band (band center is always x0), and t is time. The standard deviation of

From the following list of reactions that we have studied on the course, pick your favourite and write an account on it. Your answer should include reference to background, mechanism and application, and should contain illustrative examples of your own choosing. Aldol condensation HClaisen Dieelemann condensetien III. Knoevenagel condensation V

(c) The potential for the HOH bond angle in a water molecule can be represented by the following expression V( ) O H H 2 ( 00)2 where KHOH 0.1103 kJ moldegree . A starting structure of the water molecule, with C2v symmetry, has an angle 110.0, and the first derivative of the potential with respect to this angle has the value of 0.6045 kJ

An analytical chemist is titrating 168.4 mL of a 0.7600M solution of aniline (C,H,NH,) with a 0.8100M solution of HIO,. The p K, of aniline is 9.37. Calculate the pH of the base solution after the chemist has added 167.3 mL of the HIO, solution to it. Note for advanced students you may assume the final volume equals the initial volume of the

A chemist titrates 250.0 ml of a 0.6655 Mf sodium hydroxide (NaOH) solution with 0.3489M HNO, solution at 25 C. Calculate the pH at equivalence. Round your answer to 2 decimal places. Note for advanced students you may assume the total volume of the solution equals the initial volume plus the volume of HNO, solution added. DH 0

The calibration equation obtained by spectroscopic method for chromium (Cr) determination is Signal (1.32 x ppmCr) 0.04. An unknown sample was analyzed three times using this method and the average signal of the unknown was 26.71(0.08). SN ratio for the unknown sample is 177 217 129 334

Use each graph to estimate the half-life of polonium-211 two half-lives from the two graphs might differ slightly. If so, discuss what is different between these two graphs. Also, discuss what half-life means in the context of a single atom vs. in the context of a large sample of atoms.

H. J K Atoms Remaining vs Time 100 75 50 25 1 2 Time ... 3. Atoms Remaining

What are some hypothesis of radioactive decay single atom and multiple atoms and write some conclusion on it in brief?

What is the equilibrium constant? How many moles of ligand bind per mole of riboflavin binding protein? 0.040 mM of riboflavin binding protein was used. Riboflavin (ligand) mM Absorbance 0.025 0.025 0.050 0.038 0.075 0.045 0.100 0.056 0.125 0.058 0.150 0.065 Km = 2 mM

Identify each of the following: (a) Two aldoses whose configuration at carbons 3, 4, and 5 matches that of D-fructose. (b) The enantiomer of D-galactose. (c) An epimer of D-galactose that is also an epimer of D-mannose. (d) A ketose that has no chiral centers. (e) A ketose that has only one chiral center. (f) Monosaccharide residues of cellulose,

Consider the conversion of glyceraldehyde 3phosphate into 1,3 bisphosphoglycerate during glycolysis. If the P, used inthis reaction was uniformly labeled with 18O (see below), then how many of the labeled oxygen atoms would end up on the 3 phosphoglycerate that is formed in the later step of glycolysis (e.g., the phosphoglycerate kinase reaction)

The passivation potential of iron is a function of pH. At one time it was proposed to identify irons passive film by calculating the pH dependency of the equilibrium potential of various iron oxides and comparing them to the measured variation of the passivation potential with pH. The oxide whose equilibrium potential varied with pH in the same

Ricinoleic acid (left) is an unusual hydroxyl acid that is a major component of castor seed oil. Although ricinoleic acid isnt common in your lipid membranes, the fatty acid synthase in Ricinus communis produces it preferentially to other fatty acids. Answer the following questions about this fatty acid. HO Ricinoleic acid X OH or SCoA X OH or

20.23 The mutarotation of glucose is first order in glucose con centration and is catalyzed by acids (A) and bases (B). The first order rate constant may be expressed by an equation of the type that is encountered in reactions with parallel paths k ko kH H kaA kBB 3D where ko is the firstorder rate constant in the absence of acids and bases

3Calculate the concentration of NaCl required to make an ophthalmic solution containing 20 ml of 1.5 boric acid 0.15 atropine sulphate, isotonic with lachrymal fluid. Nacl equivalent of boric acid 0.50 Nacl equivalent of atropine 0.12 3D 3D 4 Calculate the amount of sodium chloride required to make an ophthalmic solution of 1 ephedrine

How to produce electrolytic grade copper from mixed type ore containing 1.2% CuFeS2 (chalcopyrite) and 6% Cu3 (CO3) 2 (OH) 2 (azurite)?

How much water must be added to completely dissolve 1.00g CaSO 4 at 25 degrees Celsius?

A solution of 0.40L 0.080M AgNO 3 is mixed with a solution of 0.30L 0.12M Na 2 SO4. Will there be precipitation?

1. K b for a strong base is not specified because the base is completely dissociated. 2. A strong acid has a high concentration of H 3 O + ions. 3. The pH is defined based on the water's own proteolysis and the difference between pH and pOH is always equal to 14. True or false

What is the pH of a 0.150 M Na 2 CO 3 solution?

Provide a synthesis of the following compound from the given starting materials. CH3 H3CO OCH3

1) What is the pH inside of the vacuole? The chemical potential is 0 J/mol and the temperature is 300 K. The pH outside of the vacuole is 7 and the E is -208 mV. 2) How much heat (in Joules) is given off when a photon of 550 nm is absorbed by PSII (P680)?

Rank the following compounds in order of decreasing acidity. List the most acidic first. OCH3 OCH3 OCH3 NHCH3 A B C D

Balance the following chemical equations.

1. H2 O2 2. Clz 3. O2 03 4. Na H20 5. Fe CuSO4 6. Zn HCl 7. KC103 8. Sg F2 9. Fe O2 H20 HCI NaOH H2 Cu FeSO4 ZnCl, H2 KCl O2 SF6 Fe203 10. C2H6 O2 CO2 H20 11. Balance these three equations using fractional coefficients S8 F2 C4H10 O2 CO2 H2O S8 O3 12. H2 O3 H2O (You must balance it with one restriction the

Balance the following equations.

1. H2 02 H2O 2. H2 Cl, HCI 3. 02 4. Na H20 5. Fe CuSO4 6. Zn HCl ZnCl2 H2 7. KCIO3 KCI 02 8. Sg F2 SF, 9. Fe 02 10. C2H6 O2 CO2 H20 11. Balance these three equations using fractional coefficients S8 F2 SF6 CH10 02 CO2 H20 S8 Og SO2 12. H2 O3 H2O (You must balance it with one restriction the coefficient in front of the

Determine the mole ratio of the following reactants and products. For items 1 and 2 4NH3 302 6H2O 2N2 1. What is the mole ratio of NH3 to H20 2. What is the mole ratio of O2 to N2 For items 3 and 4 SiO2 4HF SFA 2H20 3. What is the mole ratio of HF to SIF4 4. What is the mole ratio of SiO2 to SiF4 For items 5 and 6 3NO2 H20 2HNO3 NO 5. What

Balance the chemical equation below and complete its mole ratio on the table below.

C3H8 O2 CO2 H2O C3H8 O2 CO2 H2O mol 5 mol mol 4 mol 3.33 mol mol 9 mol 13.32 mol mol 26.25 mol 15.75 mol 21 mol

Identify the reactants and products in the following equations Reactants Products Fuel 02 CO2 H2O CH4 202 CO2 2H2O Zn S ZnS 2 H2(g) 02(g) 2 H20(1). 2H2 02 2H2O 8CO2 2C4H10 1302 1020 2C3H8 702 6CO 8H20 3H2 N2 2NH3 3NO2(g) H2O(1) 2HNO3(1) NO(g). 8 502 02 4H2O Fe H2O Fe304

Write the balanced chemical equation and solve each of the following. 1. Aluminum metal (Al) and hydrogen chloride (HCI) react to form aluminum chloride (AICl3) and hydrogen gas (H2). A. What is the balanced chemical equation B. How many moles of aluminum metal are needed to produce 4 moles of aluminum chloride C. How many moles of hydrogen

5. How many moles of CO2 are formed when 5 moles of ethane are consumed a. 10 mole b. 11 mole c. 8 mole d. 3 mole 6. How many mL of 0.1 M HCl are required to react with 0.01 mole of Na2CO3 (the products are NaCl and H2CO3) c. 400 mL d. 200 mL a. 100 mL b. 10 mL

Identify the reactants and products in the following equations Reactants Products Fuel 02 CO2 H2O CH4 202 CO2 2H20 Zn S ZnS 2 H2(g) 02(g) 2 H20(1). 2H2 02 2H20 2C4H10 1302 8C02 10H20 2C3H8 702 6CO 8H20 3H2 N2 2NH3 3NO2(g) H20(1) 2HNO3(1) NO(g). C3H8 502 3CO2 4H20 Fe H20Fe304

In an experiment, 30 grams of C3Hg burns in air to produce CO2. After performing the experiment 70 grams of CO2 was collected. 1. What is the actual yield 2. What is the theoretical yield 3. What is the percent yield

5. How many moles of CO2 are formed when 5 moles of ethane are consumed c. 8 mole d. 3 mole a. 10 mole b. 11 mole 6. How many mL of 0.1 M HCl are required to react with 0.01 mole of Na2CO3 (the products are NaCl and H2CO3) a. 100 mL c. 400 mL b. 10 mL d. 200 mL

1. Aluminum metal (Al) and hydrogen chloride (HCI) react to form aluminum chloride (AICI3) and hydrogen gas (H2). A. What is the balanced chemical equation B. How many moles of aluminum metal are needed to produce 4 moles of aluminum chloride C. How many moles of hydrogen chloride are needed to react with this number of moles of aluminum metal 2.

1. Aluminum metal (Al) and hydrogen chloride (HCI) react to form aluminum chloride (AICI3) and hydrogen gas (H2). A. What is the balanced chemical equation B. How many moles of aluminum metal are needed to produce 4 moles of aluminum chloride C. How many moles of hydrogen chloride are needed to react with this number of moles of aluminum metal 2.

What are IUPAC names for the following compounds?

(f) CH,(CH,),CH(CO,H) CO.H (a) CH,(CH,),CO,H (b) CH,(CH,),CO,K (c) H,CCH(CH,),CO,H (d) H,C CC (g) (CH2),CO,H H (e) HO,C(CH,),CO,H (h) CH,CH3 CH(CH,),CO,H

What importance is knowing the relationship between electrical conductivity in solutions and the molar concentration of these solutions.

Propose a mechanism for the transformation from salicylic acid to acetylsalicylic acid. CH, co,H co, CH,oCCH, CH,OH Saleylle Acid Mw I12 gimole Acetie Anhydride d 108 pml MW 101.1 gmole hp 140c Acetyhalieylie Acid MW 180.1Sgmole mp 128137C Acetic Add mp 199c

Acetic anhydride was used in excess. The excess material was quenched by adding water, from which anhydride is hydrolyzed to acetic acid. Draw the chemical reaction to represent this process, and provide an arrow-pushing mechanism.

Write a chemical equation to represent the hydrolysis of aspirin under acidic conditions. Propose a plausible arrow-pushing mechanism.

One mole of an ideal gas is subjected to several changes in state. C, 12.47 JK mol. What will be the change in temperature in each change a) 512 J of heat flows out 134 J of work are destroyed. b) 500 J of heat flows in 500 J of work are produced. c) No heat flows in 126 J of work are destroyed.

16. KFE3AISI3010(OH)2 Cu O2 H2S KAISi3Og CuFeS2 H2O 17. SiO2 CaC2 Si CaO CO2 18. NH3(g) O2(g) NO2(g) H2O(g) 19. MgNH4PO4 20. Balance PC15 H2O H3PO4 HCl using the LCM method. Mg2P207 NH3 H2O

In an experiment, 30 grams of C3H8 burns in air to produce CO2. After performing the experiment 70 grams of CO2 was collected. 1. What is the actual yield 2. What is the theoretical yield 3. What is the percent yield

A voltaic cell employs the following redox reaction PbO2 (s) NO (g) Pb2 (aq) NO, (ag) a) Balance the above reaction in acidic solution. b) Draw a diagram of the voltaic cell. Label the PbOz, NO, Pb2, and NO,. Indicate the direction of electron flow and the direction of anion and cation flow from the salt bridge. c) The PbO2 Pb2 halfreaction has

A voltaic cell employs the following redox reaction PbO2 (s) NO (g) Pb2 (aq) NO3 (ag) a) Balance the above reaction in acidic solution. b) Draw a diagram of the voltaic cell. Label the PbO2, NO, Pb2, and NO3. Indicate the direction of electron flow and the direction of anion and cation flow from the salt bridge. c) The PbO2l Pb2 halfreaction

2. Magnesium metal can be produced via the electrolysis of molten magnesium chloride harvested from seawater. a) Write a balanced chemical equation for this process. b) What mass of magnesium is produced during 10.0 h of electrolysis with a current of 50.0 A

3. N13 is used as a radiotracer to measure blood perfusion. a) Which type of radiation would you expect to be emitted by N13 Explain your answer in 12 sentences. b) Write a balanced nuclear reaction for the decay of N13. c) N13 is produced at a cyclotron by bombarding water with highenergy protons to produce 13NH3 molecules. If a 100.0 mL sample

In a nuclear reactor, the U235 atom (235.04393 amu), when hit by a neutron, may. split into many possible fission fragments such as Kr92 (91.92616 amu) and Ba141 (140.9144 amu), emitting more neutrons. a) Write a balanced nuclear reaction for the fission of U235 to form Kr92 and Ba141. b) Calculate the energy released (in joules per kilogram of

The cis isomer of tetraamminedichlorocobalt(Ill) bromide appears red while the trans isomer appears green. a) Write the formula for this compound. b) Draw the cis and trans isomers of this compound. c) Does this compound have a coordination isomer Explain your answer in 12 sentences. d) Does this compound have a linkage isomer Explain your answer

1. A voltaic cell employs the following redox reaction: PbO 2 ( s ) + NO ( g ) Pb 2+ ( aq ) + NO 3 ( aq ) a) Balance the above reaction in acidic solution. b) Draw a diagram of the voltaic cell. Label the PbO 2 , NO, Pb 2+ , and NO 3 . Indicate the direction of electron flow and the direction of anion and cation flow from the salt bridge. c)

Which type of radiation would you expect to be emitted by N-13? Explain. Write a balanced nuclear reaction for the decay of N-13.

N-13 is produced at a cyclotron by bombarding water with high-energy protons to produce 13 NH 3 molecules. If a 100.0 mL sample of water has a pH of 10.57 upon exiting the cyclotron, what is the activity of the sample in Ci? The K b of NH 3 is 1.8 x 10 5 and the half-life of N-13 is 9.97 minutes.

A. A drop of perfume evaporated in an airtight room with a volume V = 60m ^ 3. The perfume drop has m = 10 ^ -4 gr of an aromatic substance with a molecular mass u = 1 kg mol. What is the number of molecules that enter the lungs in each breath, if the volume of the lungs increases in each breath at the rate of V1 = 10 ^ -3 m ^ 3? B. What is the

Two containers with volumes V and V4 are connected to each other by a pipe whose volume is negligible. At baseline both contain nitrogen at atmospheric pressure and at a temperature of 300K. Quickly heat the large tank to 350K, refrigerate the small one to 280K. Then allow the system to reach equilibrium when it is in thermal insulation from its

We collect in a vessel, hydrogen emitted due to the passage of an electric current through an aqueous solution of acid. For 10 minutes 374 cm ^3 of hydrogen are collected at a temperature of 20 C and at atmospheric pressure. A. What is the mass of the hydrogen collected, if it is known that the density of hydrogen at atmospheric pressure and at a

A. What is the number of protons, neutrons, and electrons in a neutral sulfur atom, whose sign is: 16 S 32 ? B. What is the mass and what is the charge of the atom 18 X 38++ ? C. What is the charge in the nucleus of element U? D. Physicists have discovered a new nuclear reaction in which the isotope 75 A 150 decomposes into a 40 B 75 and another