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November 24, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
What is the significance of a potential energy diagram? What kind of global picture does it provide about the reaction?
Tuesday, November 11, 2014 at 1:10am

Science-Chemistry
What is ΔH° for vaporizing liquid water at 25°C? What is ΔS° for vaporizing liquid water at 25°C? What is ΔG° for vaporizing liquid water at 25°C?
Tuesday, November 11, 2014 at 1:01am

chemistry
a solution consisting of 1.6M NaNO3 and 1.0M of Na(NO3)2 please help
Monday, November 10, 2014 at 10:58pm

Chemistry
What is the molarity of 35.0 of NaCl in 125 mL of water?
Monday, November 10, 2014 at 9:31pm

Chemistry
How many moles of LiF would be required to produce a 12.0 M solution with a volume of 10.5 L?
Monday, November 10, 2014 at 9:03pm

Intro to Chemistry
When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced. CaCO3(s)+2HCl(aq)=CaCl2(aq)+H2O(l)+CO2(g​) How many grams of calcium chloride will be produced when 27.0 g of calcium carbonate are combined with 11.0 g of ...
Monday, November 10, 2014 at 8:49pm

Intro to Chemistry
Given the following chemical equation, determine how many grams of N2 are produced by 8.58 g of H2O2 and 5.62 g of N2H4. 2H2O2(l)+N2H4(l)=4H2O(g)+N2(g)
Monday, November 10, 2014 at 8:44pm

chemistry
In the molecular weight determination experiment, what would be the effect if some air remains in the flask after the compound was completely vaporized?
Monday, November 10, 2014 at 7:43pm

Chemistry
If a balloon containing 1000 L of gas at 50 degrees Celsius and 101.3 kPa rises to an altitude where the pressure is 27.5 kPa and the temperature is 10 degrees Celsius, its volume there is?
Monday, November 10, 2014 at 6:33pm

chemistry
How many milliliters of 5.50 M HCl must be diluted to make 350. mL of a 0.500 M solution?
Monday, November 10, 2014 at 5:34pm

chemistry
What mass of KCl (MM = 74.55 g/mol) is required to make 750 mL of a 0.275 M solution?
Monday, November 10, 2014 at 5:34pm

chemistry
The acceptable limit for nitrate, often found in well water in agricultural areas, is 10 ppm. If a water sample is found to contain 355 µg/L, determine the concentration in parts per million, ppm. Express your answer in decimal form rounded to the third decimal place. Do...
Monday, November 10, 2014 at 5:33pm

chemistry
Calculate the quantity of heat in calories absorbed when 131.01 g of water is heated from 21.1°C to 50.4°C. Enter your answer as a whole number (no decimal portion). Do not include units with your answer.
Monday, November 10, 2014 at 5:33pm

chemistry
How many milliliters of 4.50 M HCl must be diluted to make 400. mL of a 0.500 M solution?
Monday, November 10, 2014 at 3:32pm

chemistry
What mass of KCl (MM = 74.55 g/mol) is required to make 550 mL of a 0.250 M solution?
Monday, November 10, 2014 at 3:32pm

chemistry
how many moles of HCL are contained in 34.7 mL of 8.00 M solution ?
Monday, November 10, 2014 at 3:32pm

Chemistry
What would cause the molecules of gas to get closer together?
Monday, November 10, 2014 at 2:27pm

Chemistry
Consider the evaporation of water at 298 K and 1 atm pressure: H20 (l) <---> H20 (g) Given that ΔGOrxn= 8.6kJ/mol, what is the equillibrium vapor pressure of water at 298 K?
Monday, November 10, 2014 at 1:37pm

Chemistry
What is the approximate ΔH in kJ for the following reaction as written: 2NH3(g) --> 3H2(g) + N2(g) Careful, what kind of bond does the nitrogen molecule make?
Monday, November 10, 2014 at 9:46am

Chemistry
Arrange the following diatomic molecules in order of weakest to strongest bond: HF, HCl, HBr, and HI.
Monday, November 10, 2014 at 9:46am

Chemistry
Which of the following ionic compounds has the highest melting point? Help: Lattice energy Select one: a. Cs2O b. K2O c. BeO d. SrO e. LiF f. CsI
Monday, November 10, 2014 at 9:44am

chemistry
how many grams of CO are needed to react with 2.90 grams of Fe2O3?
Sunday, November 9, 2014 at 11:52pm

Chemistry 2
what is the pH in a 0.13M solution of aniline (Kb=4.3*10^-10). What is the concentration of C6HNH2 in the same solution?
Sunday, November 9, 2014 at 11:02pm

chemistry
Consider the reaction between 52.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 25.4 L of O2 at 27.0°C and a pressure of 1.65 atm. The products of the reaction are CO2(g) and H2O(g). Calculate the number of moles of H2O formed if the reaction goes to completion.
Sunday, November 9, 2014 at 9:40pm

chemistry
If 8.16 g of CuNO3 is dissolved in water to make a 0.500 M solution, what is the volume of the solution?
Sunday, November 9, 2014 at 8:56pm

Chemistry
Describe what happens to a co2 sample when the following changes are made: (a) The temperature is increased from -100°c to 0°c at constant pressure of 2 atm B) The pressure is reduced from 72 atm to 5.0 atm at a constant temperature of 30°c C) The pressure is first...
Sunday, November 9, 2014 at 7:20pm

chemistry
How do you write a balanced equation for the preparation of phenylmagnesium bromide and it's reaction with benzophenone followed by neutralization in acid?
Sunday, November 9, 2014 at 6:29pm

Chemistry
Using the following data 1. CU3+ + 2e- ---> Cu+ E1= 1.28V 2. CU2+ + e- ---> Cu+ E2= 0.15V 3. Cu2+ + 2e- ----> Cu(s) E3= 0.34V 3. Cu+ + e- ----> Cu (s) E4= 0.52V calculate the standard reduction potential for the reaction of Cu(III) to Cu(II). Is it .783 V?
Sunday, November 9, 2014 at 4:39pm

Chemistry
If there are 25 mg of water in a typical drop of water, how many drops of water would react completely with 2 mmol of phenylmagnesium bromide? How do I set up the problem?
Sunday, November 9, 2014 at 4:30pm

Chemistry
Is my answer correct? Calculate the mass of frost (water ice) on a piece of dry ice that would completely react with 2 mmol of phenylmagnesium bromide. (1/44 CO2)*(0.002mol of phenylmagnesium bromide)= 0.0000455
Sunday, November 9, 2014 at 4:28pm

Chemistry
What isthe theoretical yield of a microscale reaction of these materials in which 300 mg of bromobenzene, 50 mg of magnesium, and 350 mg of benzophenone were used?
Sunday, November 9, 2014 at 4:23pm

chemistry
What is the vapor pressure of a solution of 0.5mol of a non-volatile impurity x and 2.0 g of TaCl5 (L) at a temperature of 226 degrees celcius? The vapor pressure of TaCl5 (l) at 226 degrees celcius ,621mmHg
Sunday, November 9, 2014 at 1:49pm

chemistry
Calculate the molar mass of TaCl5 (g). when 8.95 (g) are present and occupy a volume of 715ml at a temperature of 250 degrees celcious and 1.5 atm pressure.
Sunday, November 9, 2014 at 1:45pm

Chemistry
2.The solubility of sodium chloride at 20 degrees Celsius is 358g/1000g H20, or 358g/1358g solution. How many grams of sodium chloride would you expect to dissolve in 2200 grams of H20 at 20 degrees Celsius?
Sunday, November 9, 2014 at 12:25pm

chemistry
The equilibrium constant for the chemical equation is K = 4.90 at 199 °C. Calculate the value of the Kc for the reaction at 199 °C. N2(g)+3H2(g)=2NH3(g) Kc=?????
Sunday, November 9, 2014 at 11:47am

chemistry
1. (3.0x10^4) divided by (6.2x10^1) = 5x10^2? 2. (4.7x10^-3) divided by (9x10^-4) = 5x10^-6 3. (3.0x10^4) times (6.2x10^1) =1.9x10^6 4. (4.7x10^-3) divided by (9x10^-4) =5x10^-6 5. (5.1x10^2) divided by (3x10^4)
Sunday, November 9, 2014 at 10:27am

Clinical chemistry
Prepare a 10 percent solution of sulphuric acid from a 98 percent stock solution of the acid in a 500mls beaker
Sunday, November 9, 2014 at 6:32am

Chemistry
Using the following data 1. CU3+ + 2e- ---> Cu+ E1= 1.28V 2. CU2+ + e- ---> Cu+ E2= 0.15V 3. Cu2+ + 2e- ----> Cu(s) E3= 0.34V 3. Cu+ + e- ----> Cu (s) E4= 0.52V calculate the standard reduction potential for the reaction of Cu(III) to Cu(II). Is it .783 V?
Sunday, November 9, 2014 at 4:36am

Clinical chemistry
Describe how you can prepare 0.25 molar solution of sodium hydroxide from an 80 percent stock solution in a 500mls beaker
Sunday, November 9, 2014 at 1:30am

Chemistry
If 500 mol of hydrogen gas occupies 5.00L at 25 celsius, what is the pressure in atm? I believe this is Ideal gas law. I can't figure out how to put it in the PV=nRT.
Sunday, November 9, 2014 at 12:48am

chemistry
Is it appropriate to call a soft drink an aqueous solution? Justify your answer.
Saturday, November 8, 2014 at 9:57pm

Chemistry
I'm having trouble understanding Boyle's Law and Dalton's law of partial pressures. Can anyone help me work this please? Thank you A sample of propane gas, C3H8, was collected over water at 22.5 ºC and 680. torr. The volume of the wet gas is 3.89 L. What will ...
Saturday, November 8, 2014 at 9:05pm

Chemistry
What is the density (in mg/mL) of a H2S gas at 12.9 atm and 137 K?
Saturday, November 8, 2014 at 9:00pm

Chemistry
What is the molar mass of a gas (96.0 g) in a 25.0 L container at 27.0 °C? The pressure inside the container is 3.04E5 Pa.
Saturday, November 8, 2014 at 8:18pm

Chemistry
what are the simplest molecules to synthesize a n,n-dimethyl-2-methylpropanamine
Saturday, November 8, 2014 at 6:28pm

chemistry
3. If 5.20 g of HCl is added to enough distilled water to form 3.00 L of solution, what is the molarity of the solution? [Use molecular weight: HCl, 36.46 amu] 5.20/36.46= 0.1426 X 3.00=0.428 M IS THIS CORRECT
Saturday, November 8, 2014 at 4:04pm

Chemistry
What would be the molarity of a solution made by dissolving 126g K3PO4 into 1500 mL of water?
Saturday, November 8, 2014 at 3:02pm

Science: Chemistry
1. The element gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is...
Saturday, November 8, 2014 at 2:39pm

chemistry
(3.0 x 10^4 ) ÷ (6.2 x 10^1) = 18.6x10^3 (4.7 x 10^-3 ) ÷ (9 x 10^-4) = 42.3x10^-7 (3.0 x 10^4 ) x (6.2 x 10^1) = 18.6x10^3 (5.1 x 10^2 ) x (3 x 10^4) = 15.3x10^-2
Saturday, November 8, 2014 at 2:15pm

Chemistry
1. The eleent gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is ...
Saturday, November 8, 2014 at 2:05pm

Chemistry
What is the molarity of a solution made by mixing 213.6 ml of 1.5 M NaCl with 328 ml of 4.3 M NaCl?
Saturday, November 8, 2014 at 1:50pm

Chemistry
How many hydrogen bonds can each (i) water and (ii) ice molecule form?
Saturday, November 8, 2014 at 11:11am

Chemistry
A salt may be prepared by the reaction of one salt with another salt, particularly if one of the products is insoluble. In which one of the following reactions is this demonstrated? (NH4)2CO3 + K2SO4 \->(NH4)2SO4 + K2CO3 CuCl2 + 2 NH4NO3 \-> Cu(NO3)2 + 2 NH4Cl Sr(NO3)2...
Friday, November 7, 2014 at 11:55pm

Organic Chemistry
I have a Lab assignment that requires the synthesis of carboxylic acid and our final product is Benzoic Acid. The following equation was provided: C7H8 + KMnO4 ---> MnO2 1) KMnO4, OH-, heat 2) H3O+ We were asked to balance the equation including the by-products. I was able ...
Friday, November 7, 2014 at 11:55pm

Chemistry
Calculate the mass (in grams) of sugar, C12H22O11, in 142.4 mL of a 1.39 M solution of sugar. (atomic weights: C = 12.01, H = 1.008, O = 16.00)
Friday, November 7, 2014 at 11:51pm

Chemistry
What mass (in grams) of sodium chloride, NaCl, is needed to make 422. g of a 3.39%(m/m) NaCl solution? (atomic masses: Na = 22.99, Cl = 35.45)
Friday, November 7, 2014 at 11:51pm

Chemistry
A salt may be prepared by the reaction of one salt with another salt, particularly if one of the products is insoluble. In which one of the following reactions is this demonstrated? (NH4)2CO3 + K2SO4 \(->NH4)2SO4 + K2CO3 CuCl2 + 2 NH4NO3 \->Cu(NO3)2 + 2 NH4Cl Sr(NO3)2 + ...
Friday, November 7, 2014 at 11:29pm

Chemistry
what are the simplest molecules to synthesize a n,n-dimethyl-2-methylpropanamine
Friday, November 7, 2014 at 10:48pm

chemistry
8.00g of NaOH are dissolved in water to make 4.00L of solution. What is the concentration of hydronium ions, [H3O+], in this solution? Express your answer with the appropriate units.
Friday, November 7, 2014 at 10:32pm

Chemistry
1.Calculate the density of oxygen, O2, under each of the following conditions: STP 1.00 atm and 20.0 ∘C 2.To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 4.3-L bulb, then filled it with the gas at 1.90atm and 20.0...
Friday, November 7, 2014 at 9:58pm

Chemistry Physics
How many joules of heat need to be removed to condense 1.50 kg of steam at 100°C -Specific Heat for steam is 2000 J/kg°C-
Friday, November 7, 2014 at 7:41pm

chemistry
Give a structure to match the name for the following compound. isobutyl alcohol Express your answer as a condensed structural formula.
Friday, November 7, 2014 at 4:46pm

chemistry
Give a structure to match the name for the following compound. 2-pentanol
Friday, November 7, 2014 at 4:45pm

chemistry
How do carboxylic acids and esters differ in chemical structure? Check all that may apply. Esters have a hydroxyl group. Esters have a carboxyl group. Esters have a carboxyl group and hydrogen linkage off the alpha carbon. Esters have a carboxyl group and ether linkage off the...
Friday, November 7, 2014 at 4:02pm

chemistry
How do carboxylic acids and esters differ in odor? Check all that apply. Esters smell sweeter, often fruity. Carboxylic acids have often not very pleasant smelling. Carboxylic acids smell sweeter, often fruity. Esters have often not very pleasant smelling.
Friday, November 7, 2014 at 4:01pm

chemistry
Which of the following is a fluorinated hydrocarbon? Which of the following is a fluorinated hydrocarbon? carbon tetrachloride teflon DDT chloroform
Friday, November 7, 2014 at 3:51pm

chemistry
Which of the following is a feature of an aromatic compound? Which of the following is a feature of an aromatic compound? It has a strong aroma. Its formula contains only six carbon atoms. It contains a benzene ring. It contains only carbon-carbon double bonds.
Friday, November 7, 2014 at 3:43pm

chemistry
What volume (in milliliters) of 0.496 M aqueous ammonia, NH3, could be made from 17.6 mL of concentrated aqueous ammonia (15.0 M)? (atomic masses: N = 14.01, H = 1.008)
Friday, November 7, 2014 at 2:04pm

Chemistry due soon
If the following reaction: NO(g) + 1/2O2(g) NO2(g) has the following enthalpy change: H° = -56 kJ/mol What is the enthalpy of the decomposition reaction of 2 moles of NO2? A. 112 kJ B. 56 kJ C. -56 kJ D. -112 kJ i think the answer is d
Friday, November 7, 2014 at 11:00am

Chemistry
Does the Hydrogen Bondings in ice form, break, and reform all the time, just like in water?
Friday, November 7, 2014 at 10:02am

Chemistry
Calculate the kinetic energy change in the water that occurs when 10,000lb/hr flow in a pipe that is reduced from a diameter of 2 in. to a diameter to 1 in. Any ideas on solving this? The answer is 2.7 lbf*ft.
Friday, November 7, 2014 at 9:39am

chemistry due soon
Which reaction shows that the enthalpy of formation of CS2 is Hf = 89.4 kJ/mol? A. C(s) + 2S(s) CS2(l) + 89.4 kJ B. C(s) + 2S(s) + 89.4 kJ CS2(l) C. C(s) + 2S(s) + 89.4 kJ CS2(l) + 89.4 kJ D. C(s) + 2S(s) CS2(l) I think the answer is a or b
Friday, November 7, 2014 at 9:12am

chemistry
Which of the following compounds are organic? Check all that apply. SO2 CH3F C8H18O Cu(NH3)6Cl2
Friday, November 7, 2014 at 12:21am

Chemistry
State the full electron configuration of a free nitrogen atom.
Friday, November 7, 2014 at 12:18am

chemistry
CH3-C=C-CH3 IS CLASSIFIED AS A) ALKANE B) ALKYNE C) AROMATIC COMPOUND D) HALOALKANE E) ALKENE
Friday, November 7, 2014 at 12:17am

Chemistry (EMERGENCY)
drive.google. com /viewerng/viewer?a=v&pid=sites&srcid=ZGV​mYXVsdGRvbWFpbnxnaHNpYmNoZW1pc3RyeXxneDo​xMmEwMTFhYWEwNWNiYjg0 #1-3 must be completed for homework, but my teacher failed to thoroughly explain the material to my class, and I have no idea what to do. ...
Thursday, November 6, 2014 at 11:43pm

Chemistry due soon
What is enthalpy? A. Enthalpy is the kinetic energy of a system. B. Enthalpy is the heat involved in a reaction. C. Enthalpy is the temperature of a reaction. D. Enthalpy is the mass involved in a reaction. I think the answer is a or b
Thursday, November 6, 2014 at 10:45pm

chemistry
Rank the following elements by electron affinity, from most positive to most negative EA value: tellurium, bismuth, neon, sodium, iodine i tried Te, Bi, Na, I, Ne and it was incorrect.
Thursday, November 6, 2014 at 9:16pm

Chemistry
Sort these species into isoelectronic groups. It doesn't matter which group goes in which box, so long as the correct species are grouped. Ne Mg2+ S2- Ti4+ K+ He Li+ Be2+ N3-
Thursday, November 6, 2014 at 8:48pm

Chemistry
A reaction: A(aq)+B(aq)<-->C(aq) has a standard free-energy change of –4.69 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M, respectively? I know ...
Thursday, November 6, 2014 at 8:33pm

CHEMISTRY
If the gas was instead in a cylinder with a floating, massless, frictionless piston, what would the volume of the gas be (in liters) at STP?
Thursday, November 6, 2014 at 8:04pm

Chemistry
What is the molarity of a 2.50 x 102 cm3 solution containing 560.0 g of C6H12O6?
Thursday, November 6, 2014 at 6:26pm

chemistry
Draw one of the Lewis structure of the N2O5. In each case one oxygen bridges the nitrogens (N-O-N single bond) and 2 other oxygens are bonded to each N. How many equivalent resonance structures are there that satisfy the octet rule and where O makes at most 2 bonds?
Thursday, November 6, 2014 at 5:35pm

Chemistry
Calculate the percent deviation from ideal behavior for 1.03 mol of CO2 gas in a 1.10 L container at 35.0°C, which exerts a pressure of 20.3 atm.
Thursday, November 6, 2014 at 4:53pm

chemistry
A mixture of gases has the following partial pressure for the component gases at 20 degrees Celsius: oxygen 180.0 torr, nitrogen 3200 torr, and hydrogen 246.0 torr. Calculate the pressure of the mixture.
Thursday, November 6, 2014 at 4:50pm

chemistry
A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3. Determine the pH of the solution before the addition of any KOH. The Kb of NH3 is 1.8 × 10-5. I thought that I would need a second volume to find the moles of NH3?
Thursday, November 6, 2014 at 4:39pm

Chemistry
A mouse is placed in a sealed chamber with air at 755.0 torr. This chamber is equipped with enough solid KOH to absorb any CO2 and H2O produced by the mouse. The gas volume in this chamber is measured to be exactly 1.70 L, the temperature is held constant at 305 K. After two ...
Thursday, November 6, 2014 at 4:17pm

Chemistry
If 10 cm3 of ethanol is added to 10 cm3 of water, does the initial temperature of water change upon addition of ethanol?
Thursday, November 6, 2014 at 11:40am

Chemistry
Which direct measurement would provide evidence that the energy of a substance had changed? A. temperature B. heat C. mass D. volume I think the answer is a or b
Thursday, November 6, 2014 at 10:38am

chemistry
when x gram of carbon is completely burnt in certain amount of oxygen y gram of carbondioxide is form.what mass of Co2 will be produced when 2x gram of carbon is burnt in z gram of oxygen. which law of chemistry will help me to find the answer
Thursday, November 6, 2014 at 8:43am

chemistry
What does a slash (/) mean in chemistry?
Thursday, November 6, 2014 at 8:06am

chemistry
Let's say for example I have 5g of copper in a beaker. Mass would be 5g + mass of beaker. If I add any given amount of water to the beaker containing the copper, that will change the mass of the beaker containing the copper. Am I correct so far? So then if I pour out the ...
Wednesday, November 5, 2014 at 11:56pm

Chemistry
How many grams of chlorine gas are needed to make 5.40 x 10 6 g or a solution that is 1.40 ppm chlorine by mass?
Wednesday, November 5, 2014 at 11:38pm

Chemistry
Assuming equal concentrations and complete dissociation, rank these aqueous solutions by their freezing points: Li2SO4 K3PO4 LiNO3
Wednesday, November 5, 2014 at 11:33pm

Chemistry Physics
A steel pipe 8.25 m long is installed at 45°C. Find the decrease in length when coolants at -60°C pass through the pipe
Wednesday, November 5, 2014 at 10:37pm

chemistry
what is a sigma bond
Wednesday, November 5, 2014 at 10:04pm

chemistry
a 111.4mg ore sample containing iro with acid , filtered and diluted to 200.0ml in volumetric flask. a 1000ml aliquot is transferred to a 100.ooml volumetric flask containing hrdroxylamine hydrochloride, sodium acetate and 1,10- phenanthroline and diluted to the mark . the ...
Wednesday, November 5, 2014 at 9:18pm

Chemistry
In the reaction 2HgO(s) --> 2Hg(l) + O2(g) we measure the evolution of gas to determine the rate of reaction. At the beginning of the reaction (at 0 minutes), 0.02 L of O2 is present. After 20 minutes the volume of O2 is 0.36 L. What is the rate of reaction? Question 4 ...
Wednesday, November 5, 2014 at 9:15pm

Chemistry
A person’s blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma with a potassium dichromate solution. The balance is 16H+ (aq) + 2Cr2O72- (aq) + C2H5OH (aq) 4Cr3+ (aq) + 2CO2 (g) + 11H2O (l) If 35.46 mL of 0.05961 M Cr2O72- is required to ...
Wednesday, November 5, 2014 at 9:00pm

Chemistry
if you are given the equation 2NO(g)+o2(g)->2NO2 and you are given the volume of NO is 150mL. how do you find what the volume of O2 is required (at the same pressure and temperature)?
Wednesday, November 5, 2014 at 9:00pm

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