Thursday
May 26, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Explain the relationship between the various properties of gases including pressure, temperature, volume, amount of gas, molar mass, and particle speed.
Sunday, March 27, 2016 by BB

Chemistry
Compare the diffusion rates of hydrogen and oxygen gases.
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas is collected by water displacement. The atmospheric pressure in the room is 757mmHg and the vapor pressure of water is 17.5mmHg. What is the partial pressure of hydrogen under these conditions?
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas at 57C and 1.02atm occupies a volume of 2.20L. What volume would this gas occupy at 107C and 0.789atm?
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas at 57oC and 1.02atm occupies a volume of 2.20L. What volume would this gas occupy at 107oC and 0.789atm?
Sunday, March 27, 2016 by BB

chemistry
Calculate the pH after addition of 16.36 mL of 0.1349 M HBr to 25.00 mL of 0.1444 M NH3. Kb(NH3) = 1.800e-5. Answer: 9.059 PLEASE SHOW STEPS!
Sunday, March 27, 2016 by john

chemistry
Find the quantity of heat produced when 100ml of 0.1N HCL is completely neutralised with NAOH solution
Sunday, March 27, 2016 by chinmay

Chemistry
A student needs 0.14 mol of sodium sulphate to do an analysis. the concentration of the available solution is 2.6 m/L. What volume of the solution should the student measure out? What I've tried: C=N/V V=C/N V=2.6/0.14 V=18.6 The answer in the textbook says 54 mL...
Sunday, March 27, 2016 by AlphaPrimes

Chemistry
Describe how ametallic bond is d/t from those of an ionic bond and a covalent bond.
Sunday, March 27, 2016 by Yaekob

Chemistry
how many milliliters of a 5.0 m surcrose solution would be needed to prepare 45 mL of a 4.0 M solution?
Sunday, March 27, 2016 by Addy

Chemistry
0.573 g of calcium chloride reacts with excess of 0.5 M Na3PO4 to form .523 g of isolated calcium phosphate precipitate. Determine theoretical yield, actual yield, and percent yield for this reaction.
Saturday, March 26, 2016 by Kiana

Chemistry
Under certain conditions, nitrogen gas reacts with oxygen gas to form nitrogen monoxide gas. How many total electrons are transferred for each molecule of nitrogen or oxygen?
Saturday, March 26, 2016 by Kiana

Chemistry
Calculate the empirical formula of Tylenol: C, 63.56%; H, 6.00%; N, 9.27%; O, 21.17%
Saturday, March 26, 2016 by Jamie

Algebra
Two High Schools ordered AP Chemistry text book from the same book store. A New Hampshire school has ordered 80 copies, while a Vermont school ordered only 55 copies. The store has 70 books in its warehouses in Massachusetts and 100 books in the other warehouse in New York. ...
Saturday, March 26, 2016 by Anish Panda

Chemistry
What is the pH of a solution obtained by adding 15 g deK2SO4em 150 ml NaHSO4 with Molarity of 0, 2 m. HSO4 Ka = 1, 3.10^-2
Saturday, March 26, 2016 by Arya

Chemistry
What is the salt most likely to be formed at the junction of the Fe2+ions and SiO4+
Saturday, March 26, 2016 by Eliza

Chemistry
Balance the following redox reaction occurring in an acidic solution: ClO4^-+Br2=Cl^-+BrO3^- I get the two half reactions balanced as: 6e^-+(8H^+)+ClO4^-=Cl^-+4H2O and 6H2O+Br2=2BrO3^-+(12H^+)+10e^- Then I multiply the top equation by 5 and the bottom equation by 3. The e^- ...
Saturday, March 26, 2016 by Carol

chemistry
Explain using dilution formula how to prepare 0.2M hcl acid from 37% concentrated hcl acid
Saturday, March 26, 2016 by precious

Chemistry
At a certain temperature, the reaction has Kc = 5 x 108. If a reaction mixture at equilibrium contains 0.26 M of H2 and 0.087 M of Cl2, what is the concentration of HCl?
Saturday, March 26, 2016 by Anonymous

Chemistry
At a certain temperature, the reaction has Kc = 5 x 108. If a reaction mixture at equilibrium contains 0.26 M of H2 and 0.087 M of Cl2, what is the concentration of HCl?
Saturday, March 26, 2016 by Em

Chemistry
Calculate the standard internal energy change for the formation of water at 298K. The standard enthalpy of formation of water at 298K is - 285.8 KJ/mol.
Friday, March 25, 2016 by Rohit

~ CHEMISTRY ~
If k is a constant, how will a change in volume change the pressure? Choose one set of numbers. Assign one of them to represent P and the other to represent V. What happens to P if V is assigned the larger number? What happens to P if V is assigned the lower number? Observe ...
Friday, March 25, 2016 by Anonymous

Chemistry
If 116g of butane burns in presence of 320g of oxygen, how much carbon dioxide will be produced? What is limiting reagent? So This is how I worked it out: 116gC4H10*1/58.12(molar mass of C4H10)*8 moles CO2/2 moles C4H10*44/1(molar mass of CO2)=351.27g of CO2
Friday, March 25, 2016 by Kiana

AP Chemistry
Suppose the three gases were placed at 1.00 atm and 273 K in closed containers, as shown below. A tiny hole is opened in each container, allowing each gas to diffuse into another container filled with neon gas. What is the ratio of the rate of diffusion of nitrogen to the rate...
Friday, March 25, 2016 by Anonymous

Chemistry
How can dilute a 1 M HCl solution to obtain 100 mL of HCl solution 0,1 M?
Friday, March 25, 2016 by Eliza

Chemistry
When a balloon filled with 1.249 g of hydrogen explodes, the hydrogen reacts with 9.99 g of oxygen to form water vapor. Assuming water vapor is the only product formed, how much water vapor is produced?
Friday, March 25, 2016 by Jackie

AP Chemistry
A solution is prepared by titrating a 100.0 mL sample of 0.10 M HF (Ka = 7.2 × 10-4) with 0.10 M NaOH. A)What is the pH after 20.0 mL of the 0.10 M NaOH is added? Show all calculations.
Friday, March 25, 2016 by Anonymous

chemistry
The formation constant* of [M(CN)4]2– is 7.70 × 1016, where M is a generic metal. A 0.170-mole quantity of M(NO3)2 is added to a liter of 1.040 M NaCN solution. What is the concentration of M2 ions at equilibrium?
Friday, March 25, 2016 by Emily

chemistry
Explain using the dilution formula how to prepare 0.2M HCL acid from 37% HCL acid
Friday, March 25, 2016 by precious

Chemistry
What volume of concentrated hydrochloric acid (12.0 M HCl) is required to make 2.0 liters of a 3.0 M HCl solution?
Friday, March 25, 2016 by Wilson

Chemistry
How many grams of nitrogen are present in 2 moles of HNO3?
Friday, March 25, 2016 by MOnica

Algebra
Two High Schools ordered AP Chemistry text book from the same book store. A New Hampshire school has ordered 80 copies, while a Vermont school ordered only 55 copies. The store has 70 books in its warehouses in Massachusetts and 100 books in the other warehouse in New York. ...
Friday, March 25, 2016 by Cyprian

chemistry
Explain using the dilution formula how to prepare 0.2m HCL acid from 37% HCL acid
Friday, March 25, 2016 by precious

Chemistry
using a 6.0M stock solution and a 2.5M stock solution, create two 0.01M solutions of hydrochloric acid with a 250mL volume
Friday, March 25, 2016 by Jacob

Chemistry
N2 + 3H2 =2NH3 How many molecules of H2 are represented in the reaction? How many nitrogen atoms are represented in the reactants? How many moles of NH3 are formed?
Thursday, March 24, 2016 by Camilla

Chemistry
A rigid cylinder with a moveable piston contains 50.0 liters of a gas at 30c with a pressure at 1.00atm
Thursday, March 24, 2016 by Elizabeth

chemistry
If you place 5 mg NiCO3 in 1 L of pure water, does all the salt dissolve? If not, how much salt remains undissolved? The Ksp for NiCO3 is 6.6x10^-9 M.
Thursday, March 24, 2016 by Julia

chemistry
For CaCrO4, Ksp= 7.1x 10^-4. How many grams of Na2CrO4 must be added to 200 mL of .250 M Ca(NO3)2 to just initiate precipitation?
Thursday, March 24, 2016 by Julia

Chemistry
A scuba diver 60 ft below the ocean surface inhales 55.0 mL of compressed air from a scuba tank at an initial pressure of 2.60 atm and temperature of 8 ∘C. What is the final pressure of air, in atmo-spheres, in the lungs when the gas expands to 155.0 mL at a body ...
Thursday, March 24, 2016 by Barb

Sri sankara global academy/ Chemistry
A food scientist also tested some ethanoic acid solution. Ethanoic acid is the acid which is found in vinegar.His results are shown below. vinegar ethanoic acid Volume used/Cm3 50 10 volume of NaOH needed to neutralise/cm 30 10 The ethanoic acid solution contained 10 g of acid...
Thursday, March 24, 2016 by vidya

Chemistry
Hey guys! Trying to understand this problem before my Chem exam but I just can't get it down no matter how hard I try. Detailed solutions would be greatly appreciated because I'm so lost on this one. Thanks! What mass of ammonium chloride must be added to 5.00x10^2 mL ...
Thursday, March 24, 2016 by Joce

Chemistry (30s)
I need help on this question. I can't seem to understand it. Find the molecular formula of a compound with a gram molecular mass of 30 g and an empirical formula of CH3. Please show your work! and briefly explain how you got it!
Wednesday, March 23, 2016 by Candice

AP Chemistry
A solution is prepared by titrating a 100.0 mL sample of 0.10 M HF (Ka = 7.2 × 10-4) with 0.10 M NaOH a. Does the solution contain a strong acid with a strong base, a strong acid with a weak base, a weak acid with a strong base, or a weak acid with a weak base? b. ...
Wednesday, March 23, 2016 by Anonymous

AP Chemistry
A solution is prepared by titrating a 100.0 mL sample of 0.10 M HF (Ka = 7.2 × 10-4) with 0.10 M NaOH a. Does the solution contain a strong acid with a strong base, a strong acid with a weak base, a weak acid with a strong base, or a weak acid with a weak base? b. ...
Wednesday, March 23, 2016 by jesse

Chemistry
Use the Table of Thermodynamic Data to decide which of the following reactions have K>1 at 298 K: (i) HCl(g) + NH3(g)-->NH4Cl(s) (ii) 2 Al2O3(s) + 3 Si(s)-->3 SiO2(s) + 4 Al(s) (iii) Fe(s) + H2S(g)-->FeS(s) + H2(g). Which of the products of these reactions are ...
Wednesday, March 23, 2016 by Terry

Chemistry
Using the Table of Thermodynamic Data calculate Kp at 500 K for the reaction 2 HI(g)-->I2(g) + H2(g) , if Kp at 300 K is 2.16x10-3 , assuming that delta H˚ is constant.
Wednesday, March 23, 2016 by chris

Chemistry
The Kp for the production of phosgene is 18.0. If one mole each of CO and Cl2 are mixed at the total pressure of 1 atm, what will be the partial pressure (in atm) of COCl2 after equilibrium is reached, CO(g) + Cl2(g)-->COCl2(g)
Wednesday, March 23, 2016 by chris

Chemistry
If 30.47 kilograms of hydrogen are produced, then how many kilograms of zinc have been consumed?
Wednesday, March 23, 2016 by Jackie

Chemistry
Write a balanced equation from the following statement: Zinc metal and sulfuric acid are combined to form hydrogen gas and zinc sulfate (Enter the formulas in the order they are listed. Do not leave a space between the coefficient and the formula)
Wednesday, March 23, 2016 by Jackie

chemistry
How many liters of hydrogen will be produced when 3766 g of aluminum are combined with hydrobromic acid to make aluminum bromide?
Wednesday, March 23, 2016 by cara

Chemistry
What is the entropy change of liquid glycol (in cal K-1 mol-1 ) when it freezes at -25 ˚C?the heat of fusion of glycol is 2688 cal mol-1 , and the specific heats of liquid and solid glycol are 33.8 and 20.1 cal K-1 mol-1 , respectively.
Wednesday, March 23, 2016 by chris

Chemistry
How many grams of ammonia (NH3) will be produced when 0.281 grams of nitrogen are combined with hydrogen?
Wednesday, March 23, 2016 by Alice

CHS Chemistry
73.79g of a compound MCl2 contains 28.54g of chlorine. Determine the molar mass mystery element M.
Wednesday, March 23, 2016 by Arika

Chemistry
What mass of ammonium chloride must be decomposed to prepare 134 grams of ammonia (NH3). Hydrochloric acid will also be produced.
Wednesday, March 23, 2016 by AJ

chemistry
what kind of reactions require oxidizing agent(reduced or oxidized) for example SO3->SO4 does it require oxidizing or reducing agent why?
Wednesday, March 23, 2016 by ruth

chemistry
why were you instructed to add distilled water in step 12, and possibly more distilled water in step 15? what purpose does the water serve?
Wednesday, March 23, 2016 by kayla

Chemistry
Gold has a density of 19.3 g/cm3. The thickness of a piece of gold leaf weighing 1.93 mg and covering an area of 14.5 cm2 is? I solved for volume=10000cm3 then I solved for height and got 690cm is the thickness of gold leaf. Can anyone confirm or deny?
Wednesday, March 23, 2016 by Nikela (Plz Check my answer)

Chemistry
You dissolve 6g of Co(ClO4)2 (molar mass: 257.83) in 1 liter of water. Assuming the entire sample dissolves, how many individual perchlorate ions are present in this solution? I'm so lost where to start.
Wednesday, March 23, 2016 by Nikela

Chemistry
A compound of B and H is found to have a mass percent composition of 81.1% Boron. Its empirical formula is B2H5. A mass spectrometry experiment tells us that the molecular mass is 53.3 g/mol. What is its molecular formula? So I feel like this is a trick question, because I ...
Wednesday, March 23, 2016 by Nikela

Chemistry
Consider the chemical equation. 2H2 + O2 -> 2H2O What is the percent yield of H2O if 87.0 g of H2O is produced by combining 95.0 g of O2 and 11.0 g of H2? a 56.5% b 59.0% c 88.5% d 99.7%
Wednesday, March 23, 2016 by Kelly

Chemistry
The solubility of sodium chloride is 35.9/100 ml in STP, try dissolving 1 kg of salt in 1 l of water what happens? how much salt will be dissolved and how much salt will be insoluble?
Wednesday, March 23, 2016 by Anna

chemistry
3NO2(g) + H2O(l) → 2HNO3(l) + NO(g) How many moles of nitric acid are produced starting from 5.00 moles of NO2(g) and 2.00 moles of water? Please help,
Wednesday, March 23, 2016 by Sarah

Chemistry
If a mothball (C10H8) has a mass of 1.32 grams, how many naphthalene molecules does it contain? If I'm right just multiply 1.32g by 6.022*10^23 and the answer is 7.949*10^23 molecules. Is this right?
Wednesday, March 23, 2016 by Karisa (Check Answer)

Chemistry
What is the percent yield of the reaction below if 2.23g of hydrogen gas react with 55.3 g of iodine to produce 43.1g of HI. use the equation below: H2+I2=2HI the answers: a) 21.8 b) 77.3 c) 33.7 d) 87.1 I started by trying to find the limiting reagent. I multiplied the 2.23 g...
Tuesday, March 22, 2016 by John

Chemistry lab
A 1.340gram sample of an unknown acid, H3A, was placed in a 250.0 mL volumetric flask and diluted to volume with water. A 45.35 mL sample of this acid solution was titrated with 37.77 mL of a 0.1006M NaOH solution. A) Using one set - up dimensional analysis B) Calculate the ...
Tuesday, March 22, 2016 by Stacy

Chemistry
A certain compound contains 8.74% Carbon, 13.8% Fluorine, 77.4% Chlorine by weight. A possible molecular formula for this compound might be? I think the answer is CF2Cl26 multipy mass of each element by the percent: c: 12.01*.0874=1.049674 F: 19*.138=2.622 Cl: 35.45*.774=27....
Tuesday, March 22, 2016 by Karisa

Chemistry
Which four salts could undergo hydrolysis to act as buffers if added to their parent acid or base? KF KH2PO4 NaCl KBr NaClO4 C5H5NH3Cl NH4Cl
Tuesday, March 22, 2016 by Mikah

Chemistry
Which three substances' conjugates cannot act as buffers? i.e. There are no weak conjugates in the compounds. NH3 C6H5COOH H3PO4 NaHCO3 C5H5N HBr HF NaOH HClO4
Tuesday, March 22, 2016 by Mikah

Chemistry
a) If you have 5 dinitrogen monoxide molecules, how many nitrogen atoms do you have? b) If I had 5 moles of dinitrogen monoxide molecules, how many individual nitrogen atoms would I have? I think the answer for A is 6 nitrogen atoms. but I have no idea on B.
Tuesday, March 22, 2016 by Mae

Chemistry
Mothballs are composed of a chemical called naphthalene which has a formula of C10H8 a) what is the mass of a single naphthalene molecule in amu? b) what is the molar mass of naphthalene? c) what is the mass of a single naphthalene molecule in grams? I think I got b: 128.16 g/...
Tuesday, March 22, 2016 by Kiana

Chemistry
How many moles of compound are present in 17g of Fe2O3? I think I know how to do this, so if someone can show me so I can check my work against it. My answer was .106 moles of Fe2O3.
Tuesday, March 22, 2016 by Kiana

Chemistry
a) how many moles of atoms are in 1 mole of Ca3(PO3)2 b)If I have 1 mole of Ca3(PO3)2, how many moles of PO3^3- ions do I have? c)How many individual PO3^3- ions do I have?
Tuesday, March 22, 2016 by Kiana

Chemistry
125.0g each of two solids, lead (II) nitrate and pottassiuk iodide are dissolved in the same beaker. A reaction occurs that produces a precipitate. How many grams of precipitate are produced in the reaction?
Tuesday, March 22, 2016 by Lowery

Chemistry
What is the total mass of KNO3 that must be dissolved in 50 g of water at 60 degree C to make a saturated solution?
Tuesday, March 22, 2016 by Michael

Chemistry
20ml H2SO4 and 10ml HCl can be neutralized by 20ml NaOH (0.1M) separately.Calculate the pH of the acids?
Tuesday, March 22, 2016 by Obama

Grade 11 Chemistry
Why does methanol dissolve well in water. Explain using a diagram. I know that both H2O and CH3OH are polar, however what would I use for the diagram?
Tuesday, March 22, 2016 by Adobe

Chemistry
If all of the SCN- was not converted completely converted to FeNCS^2+ when the calibration curve was prepared, would this raise or lower the value of Keq? Explain
Tuesday, March 22, 2016 by Lyndsay

Chemistry - Gas Laws
Pressurized carbon dioxide inflators can be used to inflate a bicycle tire in the event of a flat. These inflators use metal cartridges that contain 16.0 g of carbon dioxide. At 295 K, to what pressure (in psi) can the carbon dioxide in the cartridge inflate a 3.15-L mountain ...
Tuesday, March 22, 2016 by Anna

Chemistry
for the redox reaction given in the chemical equation Pb(OH)4^2- (aq) + ClO- (aq) --> PbO2 (s) + Cl- (aq) For the oxidation half reaction I got Pb(OH)4^2- (aq) --> PbO2 (s) + 2H2O (l) + 2e- For the reduction half reaction I got 2e- + 2H2O(l) + ClO-(aq) --> Cl- (aq) + ...
Tuesday, March 22, 2016 by Anonymous

chemistry
A sample of water is known to contain 1.51 × 10^24 H2O molecules. How many moles of H2O molecules are present in the sample?
Tuesday, March 22, 2016 by Dave

Chemistry
Determine the pH of a 0,050M solution of lactic acid, CH3CH(OH)COOH (ka = 1.4x10^-4) and delta Grxn^o at 25 degrees C. Determine pH and delta Grxn^o at 25 degrees C I'm having trouble on getting started.
Tuesday, March 22, 2016 by Anonymous

chemistry
A reaction mixture of N2O4 and NO2 absorbs the heat given off in the combustion of 6.35 L CH4 measured at 24.7 C and 812 Torr. How many moles of N2O4 can be converted to NO2 as a result? CH4 + 2O2 --> CO2 + 2H2O Delta H = -890.3 KJ N2O4 --> 2NO2 Delta H = +57.2 KJ
Tuesday, March 22, 2016 by maddie

chemistry
how many grams of solid calcium oxide must react with excess water to liberate the same quantity of heat as does the combustion of 24.4 l of methane gas (CH4), measures ar 24.7 c and 753 torr? CaO +H2O --> Ca(OH)2 Delta H = -65.2 KJ CH4 + 2O2 --> CO2 +2H20 Delta H=-890.3...
Tuesday, March 22, 2016 by maddie

Chemistry
What is the solubility of X in mol/dm3 if 25cm3 of its saturated solution contains 4.0g of X (Molar mass of X=60)
Monday, March 21, 2016 by Toyety

chemistry
what type of a ligand would 18 crown 6 ether be? hexadentate?
Monday, March 21, 2016 by Anonymous

Chemistry
If you had observed the fate of an ice cube at 25 degrees Celsius, what would you conclude about the spontaneity of the process H2O (s) <-> H2O (l) ? I know for it to be spontaneous, delta G has to be negative, but how can I determine the delta G with the info given in ...
Monday, March 21, 2016 by Chelsea

Chemistry
Name the two functional groups found in benzyl acetate? Name the three functional groups found in PABA? Name the two functional groups found in Benzophenone
Monday, March 21, 2016 by Anonymous

Chemistry
name the three fundamental particles present in an atom
Monday, March 21, 2016 by Muluta Shalifu

chemistry
How do I make imgur dot com/kvxVZEv from cyclohexanone. Stork enamine synthesis results in a primary alcohol but I need secondary alcohol with one more carbon atom at right end.
Monday, March 21, 2016 by r.sh

chemistry
CH3-C(Cl)(C2H5)-CH(CH3)-C(NH2)(Br)-CH2-C​H2-C(CH3)3 IUPAC name of this compound
Monday, March 21, 2016 by Anonymous

Chemistry
How many grams of potassium nitrate, KNO3 are required to make 250 mL solution with a molarity of 0.40 M?
Monday, March 21, 2016 by Veronica

chemistry
(7 points) 1. The reaction that you just witnessed in while doing your titration was: HCl + NaOH  H2O + NaCl. This equation is balanced. Your unknown solutions contained HCl solutions of unknown concentrations, and your titrant was a 0.75 M solution of NaOH. Use the ...
Monday, March 21, 2016 by kat

Chemistry
A student used 5.06g of copper sulphate pentahydrate and salicyclic acid in the performance of the experiment. The student recovered 3.094g of salicyclic acid and 2.146g of copper sulphate pentahydrate. What is wrong with the student's result? How might this error have ...
Monday, March 21, 2016 by Tolu

chemistry
A 0.109g sample of a pure gaseous compound occupies 112ml at 100degrees and 750torr: what is the molecular weight of the compound. ANS=(30.2g,mol). Please I need the solution
Monday, March 21, 2016 by charles

chemistry 1020
You have 67.0 mL of a 0.400 M stock solution that must be diluted to 0.100 M. Assuming the volumes are additive, how much water should you add?
Sunday, March 20, 2016 by Anonymous

chemistry
Consider the following mechanism: STEP 1: A ---> B +C (slow) STEP 2: C+D ---> E (fast) OVERALL: A+D---> B+E Determine the rate law for the overall reaction (where the overall rate constant is represented as k). please help me. how do i do this problem?
Sunday, March 20, 2016 by Anna

Chemistry
The first part of this questions answer is 4.291975376e-4 What mass of KI must be added for PbI2 to form? Answer in units of g.
Sunday, March 20, 2016 by Jacaria

Science AP Chemistry
It is necessary to add iodide ions to precipitate the lead(II) ions from 250 mL of 0.076 M Pb(NO3)2(aq). What minimum iodide ion concentration is required for the onset of PbI2 precipitation? The solubility product of PbI2 is 1.4 × 10−8 . Answer in units of mol/L. ...
Sunday, March 20, 2016 by Jacaria

Chemistry
Which two conjugates could not undergo hydrolysis to act as buffers? C6H5COO- H2PO4- NH4+ ClO4- C5H5NH3+ F- Br-
Sunday, March 20, 2016 by Mikah

Chemistry
When 28g calcium reacts with 25 grams oxygen, how many grams calcium oxide form? I have 2Ca+ 2O2= 4CaO its is not working. Stoichemistry. I have the Ca as the reactant that is limiting? Please help.
Sunday, March 20, 2016 by Sarah

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