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November 27, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
The concentration of glucose in blood is 5.67%m/v. How many grams of glucose would be found in an adult male with a blood volume of 5.2L?
Sunday, July 13, 2014 at 7:35pm

Chemistry
At the instant that an elastic falling object strikes the ground and becomes compressed, which of the following energy transformations occurs? A. Gravitational to electric B. Potential to kinetic C. Electric to gravitational D. Kinetic to potential I think it is D.
Sunday, July 13, 2014 at 5:10pm

Chemistry
Three liquids of differing densities are studied. Samples of liquid 1 and liquid 2 are placed in a container together. Liquid 1 rises to the top. Another sample of liquid 1 is placed in a different container together with liquid 3. This time, liquid 3 rises to the top. If all ...
Sunday, July 13, 2014 at 3:09pm

Chemistry
Determine the density of methane (CH4) in g/L at 27.8oC and 1.1 atm.
Sunday, July 13, 2014 at 2:09pm

Chemistry
A volume of 0.155 L of a gas at STP weighs 0.412 g. Calculate the molar mass of the gas.
Sunday, July 13, 2014 at 2:08pm

Chemistry
NaOH + HS0-+ Hp + NaS0 24 24 Which of the following is the number of moles of NaOH required to neutralize 1 mole of H2S04 in the equation above? (Note: The reaction is not balanced.) A. 0.5 moles B. 1 mole C. 1.5 moles D. 2 moles 1
Sunday, July 13, 2014 at 11:50am

chemistry
. A student wants to design an experiment to demonstrate the effects of acid rain on plant life. Which of the following substances should be combined with water to best simulate acid rain? A. Vinegar B. Table salt C. Baking soda D. Ammonia
Sunday, July 13, 2014 at 11:40am

Chemistry step by step thank a lot
10L of hard water required 5.6g of lime for removing hardness. Hence temporary hardness in ppm of cac03 The answer 1000 Who helps me to solve it for me step by step clearly Thank a lot all tutors
Sunday, July 13, 2014 at 11:27am

chemistry
A certain reaction has an activation energy of 25.14 kJ/mol. At what Kelvin temperature will the reaction proceed 8.00 times faster than it did at 305 K?
Sunday, July 13, 2014 at 11:12am

chemistry
Consider the following mechanism. Step1: A+B<---->c (equilibrium) Step 2: C+A---->d (slow). Overall: 2A+B---->D. Determine the rate law for the overall reaction (where the overall rate constant is represented as k).
Sunday, July 13, 2014 at 10:39am

chemistry
Consider the following mechanism. Step1: 2A--->B (SLOW) Step2: B+C--->D (fast) Overaall: 2A+C--> D Determine the rate law for the overall reaction (where the overall rate constant is represented as k).
Sunday, July 13, 2014 at 10:36am

chemistry
The activation energy for a particular reaction is Ea = 14.80 kJ. What percentage of the molecules are at or above the activation energy at 500.0 K?
Sunday, July 13, 2014 at 10:32am

chemistry step bystep thank a lot
10L of hard water required 5.6g of line for removing hardness. Hence temporary hardness in ppm of cac03. The answer 1000 ppm= 1mg/1L cac03 = 100 g/mol who solve it for me clearly step by step Thank a lot all tutors
Saturday, July 12, 2014 at 9:44pm

chemistry step by step for me clearly
Al2(s04)3 solution of a molal concentration is present in 1 litre solution of 2.684g/cc. How many moles of bas04 would be precipitated on adding bacl2 in excess. The answer 6M I want some tutors to explain for me step by step clearly. I do not still understand Thank a lot all ...
Saturday, July 12, 2014 at 10:36am

CHEMISTRY
The solubility of KClO3 in 25 oC is 10 g solute per 100 g water if 15 g of KClO3 is embedded in 100 g water in 25 oC , then , what is the amount of KClO3 that can be dissolved ? is the solution unsaturated , saturated , or super saturated ? thank you
Saturday, July 12, 2014 at 7:51am

CHEMISTRY
Dye of iodine is prepared by dissolving in ethanol , and 1% ( one percent ) of this solution contains 10 g of solute in 1000 g of solution 1) how many grams of solvent is there in the solution ? 2) how many moles of solute ( I2) is there? 3) what is the molality of 1% of this ...
Saturday, July 12, 2014 at 7:46am

chemistry step by step thank a lot
Al2(s04)3 solution of a molal concentration is present in 1 litre solution of 2.684g/cc. How many moles of bas04 would be precipitated on adding bacl2 in excess? the answer 6M Who helps me step by step for me clearly I am thankful to all tutors
Friday, July 11, 2014 at 11:25pm

chemistry
explain whether using solid sodium hydroxide pellets rather than aqueous sodium hydroxide would alter the enthalpy
Friday, July 11, 2014 at 10:12pm

Soil Chemistry
how is carbon dioxide different than water in terms of the behavior of each compound in Earth's atmosphere?
Friday, July 11, 2014 at 8:39pm

Chemistry
Write an equation for the reaction that takes place when each base is added to water. A) LiOH B) (CH3)2NH.
Friday, July 11, 2014 at 6:19pm

chemistry
Why would you have to subtract the heat capacity of the calorimeter when calculating the heat of the reaction?
Friday, July 11, 2014 at 5:21pm

chemistry
what mass of ethanol could form from fermentation of 90.0g of glucose? what is the percentage yield if 6.0g of ethanol forms?
Friday, July 11, 2014 at 3:39pm

chemistry
Why would you have to subtract the heat capacity of the calorimeter when calculating the heat of the reaction?
Friday, July 11, 2014 at 2:16pm

chemistry
calculatethe volume of o2 and volume of al needed photon combusion on 18 kg at carbon
Friday, July 11, 2014 at 12:05pm

chemistry
calculate the volume of o2 and volume al needs photon combison on 18 kg at carbon
Friday, July 11, 2014 at 11:58am

chemistry
We can build the model in a spreadsheet simulating ten layers in the filter. For each layer we calculate the headloss with Carmen-Kozeny and calculate from this the pressures as a function of the place in the filter. Calculate the headloss and the actual pressure in each layer...
Friday, July 11, 2014 at 6:40am

Chemistry
You are a work study student in our chemistry department. Amy, your supervisor has just asked you to prepare 250ml of 2.00M H2SO4 solution for tomorrow's undergraduate experiment. The Stock Solutions cabinet is under the Stockroom Explorer. You will find find a 2.50 liter ...
Thursday, July 10, 2014 at 9:12pm

chemistry
a block of metal has a volume of 13.4in^3 and a weight of 5.14 lb. what is its density in grams per cm^3? Show operation
Thursday, July 10, 2014 at 8:41am

CHEMISTRY
Is these two electrodes appropriate to create a good battery ? : Cd => Cd^+2 + 2e- and Fe => Fe^+2 + 2e- Explain
Thursday, July 10, 2014 at 8:19am

CHEMISTRY
If a nickel rod embedded in a silver nitrate solution , what do we predict ? explain
Thursday, July 10, 2014 at 8:09am

CHEMISTRY
Assuming that this half cell I2 + 2e- + =>2I- as standard electrode and assumed its potential that is 0.00 V : a) what is standard potential of this half cell : Br2 + 2e- + => 2Br- b) what is standard potential of this half cell : Al^+3 + 3e- => Al
Thursday, July 10, 2014 at 7:57am

CHEMISTRY
Can a substance made of zinc be coated by nickel , using nickel nitrate solution ? How ?
Thursday, July 10, 2014 at 6:42am

CHEMISTRY
In electrolysis , which reaction does occur on the cathode , half oxidation reaction or reduction ?
Thursday, July 10, 2014 at 6:32am

CHEMISTRY
Why can't we use water in electrolytic cell during producing aluminium ?
Thursday, July 10, 2014 at 6:23am

CHEMISTRY
Why does hydrogen electrode have 0.00 V ? or assumed that has 0.00 V ?
Thursday, July 10, 2014 at 6:14am

CHEMISTRY
why dry cells are called dry while they contain water ? in electrochemistry
Thursday, July 10, 2014 at 6:08am

CHEMISTRY
The standard potential of this cell Sn|Sn^+2 || Cr^+3|Cr is -0.60 V , what is the reductional standard potential of Cr^+3|Cr ? if we know that reduction potential of Sn is Sn^+2 + 2e- <==> Sn : -0.14 V
Thursday, July 10, 2014 at 5:38am

chemistry
how to find which is quantum number and magnetic quantum number
Thursday, July 10, 2014 at 4:22am

Chemistry
A mixture of ammonia and oxygen is prepared by combining 0.250 L of NH3 (measured at 0.700 atm and 20°C) with 0.160 L of O2 (measured at 0.720 atm and 49°C). How many milliliters of N2 (measured at 0.740 atm and 100. °C) could be formed if the following reaction ...
Wednesday, July 9, 2014 at 4:26pm

Chemistry
Methane is formed in landfills by the action of certain bacteria on buried organic matter. If a sample of methane collected from a landfill has a volume of 200. mL at 741 torr and 27.2 °C, how many grams of methane are in the sample? I get the PV=nRT p is 741/760= .975 V ...
Wednesday, July 9, 2014 at 3:43pm

Chemistry
How much ethylene glycol (C2H6O2, the major component of antifreeze) must be added to 1 L of water to keep from it freezing at -15 °F?
Wednesday, July 9, 2014 at 10:37am

CHEMISTRY
What is the function ( or role ) of platinum in electrochemistry in general ? I read a question about platinum in electric potential , and in standard electrode potential ?! thank you a lot
Wednesday, July 9, 2014 at 9:37am

CHEMISTRY
How many oxidation states Should a substance have at least to undergo Disproportionation reaction ? thanks
Wednesday, July 9, 2014 at 9:31am

CHEMISTRY
A substance contains an element at its probable maximum oxidation number , does this substance have a maximum chance to be an oxidizing agent or have a minimum chance to be a reducing agent ? thank you
Wednesday, July 9, 2014 at 9:26am

CHEMISTRY
I have trouble finding out the oxidation number of each element in the : [Cr(N2h4CO)6]4[Cr(CN)6]3
Wednesday, July 9, 2014 at 5:58am

CHEMISTRY
I have these equations in our book , but I've tried a few times to solve it in half reaction method , but I couldn't yet : 1) KMnO4 + KIO3 => MnO2 + KIO4 ( in a basic solution ) 2) MnO4- + Cl- => Mn^+2 + HClO ( in a acidic solution ) I think these are incorrect...
Wednesday, July 9, 2014 at 5:56am

chemistry
FIND THE PERCENTAGE BY VOLUME COMPOSITION OF A VINEGAR SOLUTION CONTAINING 10cm (TO THE POWER OF 3) OF ACETIC ACID AND 190 (TO THE POWER OF 3)OF H2O
Wednesday, July 9, 2014 at 4:40am

chemistry
if you need 50.0 grams of lead2 chloride how much magnesium chloride would you need?
Wednesday, July 9, 2014 at 12:34am

chemistry
What is the mass of water obtained when mix 100.0 mL of 2.5 M. HNO3 with 100.0 mL of 2.55 M. KOH?
Tuesday, July 8, 2014 at 8:49pm

CHEMISTRY
Balance the oxidation reduction equation in half reaction PbO2 + KCl => KClO + KPb(OH)3 thank you a lot
Tuesday, July 8, 2014 at 2:25pm

Chemistry
How many milliliters of O2 are consumed in the complete combustion of a sample of hexane, C6H14, if the reaction produces 325 mL of CO2? Assume all gas volumes are measured at the same temperature and pressure. The reaction is 2C6H14(g) + 19O2(g) -> 12CO2(g) + 14H2O(g)
Tuesday, July 8, 2014 at 12:50pm

Chemistry
A mixture of ammonia and oxygen is prepared by combining 0.330 L of NH3 (measured at 0.790 atm and 22°C) with 0.210 L of O2 (measured at 0.820 atm and 48°C). How many milliliters of N2 (measured at 0.740 atm and 100. °C) could be formed if the following reaction ...
Tuesday, July 8, 2014 at 12:48pm

Chemistry
When a sample of neon with a volume of 683 mL and a pressure of 0.792 atm was heated from 19.0 to 76.0 °C, its volume became 733 mL. What was its final pressure (in atm)?
Tuesday, July 8, 2014 at 12:47pm

Chemistry
Methane is formed in landfills by the action of certain bacteria on buried organic matter. If a sample of methane collected from a landfill has a volume of 200. mL at 741 torr and 27.2 °C, how many grams of methane are in the sample?
Tuesday, July 8, 2014 at 12:47pm

Chemistry
A mixture of N2, O2, and CO2 has a total pressure of 928. torr. In this mixture the partial pressure of N2 is 31.0 cm Hg and the partial pressure of O2 is 4.00 dm Hg. What is the partial pressure of the CO2 (in torr)?
Tuesday, July 8, 2014 at 12:47pm

Chemistry
A 56 g sample of peanut oil has a volume of 60.9 cm^3. Calculate the density of the peanut oil.
Tuesday, July 8, 2014 at 12:42pm

chemistry
A student didn’t read step 4 in the procedure and assembled the cells based on Figure 1, connecting the device to the ammeter right away. When she gets to step 5 she realizes her error, but instead of estimating the initial reaction time she simply notes note the current ...
Tuesday, July 8, 2014 at 9:46am

chemistry
When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g), if 48.6 g of Mg and 150.0 g of HCl are allowed to react, ...
Tuesday, July 8, 2014 at 9:31am

CHEMISTRY
Why the oxidation number of ( H ) is -1 in 1) N2H4 2) CaH2 while ( N ) is different from ( Ca ) ?
Tuesday, July 8, 2014 at 8:53am

CHEMISTRY
In half reaction method of the chemical equation balancing , how about those redox reactions that they don't contain any (H) and ( O ) atoms ?
Tuesday, July 8, 2014 at 8:01am

CHEMISTRY
In relative oxidizing and reducing agents table ; 1) Is Al oxidized by Ni+2 2) Is Cu oxidized by Ag+ 3) Is Pb oxidized by Na+ 4) Is F2 reduced by Cl- 5) Is Br2 reduced by Cl- and if you or no , how it is as a rule to predict any ? thank you
Tuesday, July 8, 2014 at 7:58am

CHEMISTRY
Assume that the ( S ) ( S ; alphabet ) is the solubility in mol/L of AB2 compound , , then what is the concentration of A and B ? and what is the Ksp of AB2 compound ? thank you a lot
Tuesday, July 8, 2014 at 2:56am

CHEMISTRY
The Ksp of (hydroxyapatite ) Ca5(PO4)3OH is 6.8 * 10^-37 , and its molar concentration is 2.7 * 10^-5 mol/L ,, if this (hydroxyapatite) reacts with fluoride , then the F- ions replace OH- ions and the product is Ca5(PO4)3F ,, if we know the Ksp of ( fluoroapatite ) is 1.0 * 10...
Tuesday, July 8, 2014 at 2:53am

chemistry
Calculate the value of q for each of the experiments listed below. (Assume the heat capacity of water is 4.1801 J/g*C). Exp1: 2.48g of an unknown salt added to 160. mL of water resulted in a change of temperature of -0.1 C. Exp2: 2.48g of an unknown salt added to 160. mL of ...
Monday, July 7, 2014 at 8:53pm

chemistry
Balance by oxidation method the SO2 + MnO4+H2O --MnSO4+H2SO4+SO4(-2)
Monday, July 7, 2014 at 7:30pm

chemistry
Insert a complete data table, including appropriate significant figures and units, in the space below. Also include any observations you made over the course of Part I. Aluminum Measured Mass of Metal 41.66 g Distilled Water Measurement 25 mL Distilled Water Temperature 25 C ...
Monday, July 7, 2014 at 4:37pm

chemistry
What are the consequences of using only a very dilute solution of HCl or a very concentrated solution of HCl in attempting to return the pH? in attempting to return the pH to 7? What is a better alternative?
Monday, July 7, 2014 at 3:34pm

chemistry
2HCl + Mg ---> H2 + MgCl2 How can I differ what is what? 2HCL= Mg = --- H2 = MgC12 =
Monday, July 7, 2014 at 3:26pm

chemistry
The equilibrium constant of the reaction CH3COOH (l)+C2H5OH (l)=CH3COOC2H5+H2O is 4.if one mole of each of acetic acid and ethyl alcohol are heated in presence of little concentrated H2SO4 at equilibrium the amount of ester present is?
Monday, July 7, 2014 at 12:46pm

chemistry
a concrete block is heated from by 30 degree C to 50 degree C. The mass of the block is 10kg. Specific heat of concrete is 800J/Kg degree Celcius. Calculate the energy transferred.
Monday, July 7, 2014 at 11:54am

CHEMISTRY
Does it produce precipitate if 1.7 g of AgNO3 and 14.5 g of NaCl solvated in 200 mL water to get a solution in 25 oC ? thank you
Monday, July 7, 2014 at 10:32am

CHEMISTRY
If 2.5 * 10^-2 g of Fe(NO3)3 added to 100mL of 1.0 * 10^-4 M NaOH solution , will it produce precipitate ? thank you
Monday, July 7, 2014 at 10:27am

chemistry
The equilibrium constant of the reaction CH3COOH (l)+C2H5OH (l)=CH3COOC2H5+H2O is 4.if one mole of each of acetic acid and ethyl alcohol are heated in presence of little concentrated H2SO4 at equilibrium the amount of ester present is?
Monday, July 7, 2014 at 9:50am

chemistry
4g NaOH is dissolved in 100mL of 2.5M H2SO4 will be required for its complete neutralization?
Monday, July 7, 2014 at 9:11am

Chemistry
If a solution of formic acid contains 0.2 M HCHO2, 0.006 M CHO2-, and 0.006 M H+, What is the Ka of the acid? What is the ph of the solution at the concentrations given? What would happen to the equilibrium position if more CHO2- were added to the solution?
Monday, July 7, 2014 at 9:01am

chemistry solution preparations
how can we prepare 0.5 n solution of hcl as we have 37% hcl and 0.1n hcl. and we want to make 0.5n hcl from 0.1n hcl by pouring 37% hcl?
Monday, July 7, 2014 at 6:06am

CHEMISTRY
Which conditions ( reactant concentration , pressure , and temperature ) elevate high concentration of the underlines in these following equilibrium systems : 1) 2CO + O2 <==> 2CO2 + 167 kJ 2) Cu^+2 + 4NH3 <==> [ Cu(NH3)4 ]^+2 + 24 kJ 3) 2HI + 12.6 kJ <==> H2...
Monday, July 7, 2014 at 4:58am

CHEMISTRY
We have this following gas equilibrium : H2 + Cl2 <==> 2HCl + 184 kJ then predict the following to know Le chatlier's prediction 1) adding Cl2 2) removing HCl 3) elevation of pressure 4) lowering of the temperature 5) removing H2 and lowering pressure 6) adding ...
Monday, July 7, 2014 at 4:31am

chemistry, biology
Calculate the pH of a solution obtained by adding 20 mL of .2M KOH to 480 mL to .02M isoelectric glycine
Sunday, July 6, 2014 at 11:25pm

chemistry
How many mol of Argon is required to exert a pressure of 1.00 MPa at 50 ºC in a vessel that has a volume of 14 litres? (R = 8.314 J K^-1 mol^-1)
Sunday, July 6, 2014 at 9:02pm

chemistry
What is the volume of 14 mol of ideal gas if its pressure is 233 kPa and its temperature is 140 ºC? (1 mol of ideal gas at STP occupies 22.4 L).
Sunday, July 6, 2014 at 9:01pm

chemistry
2.00 m^3 of nitrogen gas at 14 ºC and 100 kPa is compressed to occupy 0.50 m^3. and its temperature rises to 42 ºC. Calculate the new pressure of the gas
Sunday, July 6, 2014 at 9:01pm

chemistry
calculate the mass of water contained in 4.021 m^3 of saturated air at 27 ºCgiven that the saturate d vapour pressure of water at 27 ºC is 3.53 kPa. (RMM of water is 18.02, R = 8.314 J K-1 mol^-1
Sunday, July 6, 2014 at 9:00pm

Chemistry
Express the concentration of a 0.0900 M aqueous solution of fluoride, F–, in mass percentage and in parts per million. Assume the density of the solution is 1.00 g/mL.
Sunday, July 6, 2014 at 8:53pm

chemistry step by step for thank a lot
10L of hard water required 5.6g of lime for removing hardness. Hence temporary hardness in ppm of caco3. The answer 1000 who helps me to solve it for me step by step thank a lot
Sunday, July 6, 2014 at 7:39pm

chemistry step by step for me thank a lot
What is the weight of ca(oh)2 required for 10 litre of water remove temporary hardness of 100 ppm due to ca(H03)2 The answer 0.74 Thank all tutors for your help Pls show step by step for me
Sunday, July 6, 2014 at 3:29pm

chemistry step by step thank a lot
342gm of 20% by mass of ba (OH)2 solution sq gr 0.57 is reacted with 1200ml of 2M hn03. If the final density is same as pure water then molarity of the ion in resulting solution by nature of the above solution is dentified 0.888m Who solve it for me step by step thank a lot
Sunday, July 6, 2014 at 2:15pm

Chemistry
When 3.15 g of a nonelectrolyte solute is dissolved in water to make 135 mL of solution at 21 °C, the solution exerts an osmotic pressure of 869 torr. What is the molar mass of the solute? What is the molar concentration of the solution? How many moles of solute are in the...
Sunday, July 6, 2014 at 1:38pm

Soil Chemistry
Understanding the strengths of carbon halogen bonds can help us to understand the behavior of CFCs and related molecules. Arrange the members of the set of carbon halogen bonds shown below in the order of bond strength. A) carbon dioxide B) methane C) ozone D) water A) c > ...
Sunday, July 6, 2014 at 11:01am

chemistry
What must be the velocity of a beam of electron if they are to display a de broglie wavelength of 1A°?
Sunday, July 6, 2014 at 7:59am

CHEMISTRY
The enthalpy change of an endothermic reaction is 8 kJ , and this reaction is spontaneous at 25 oC ,, what is the expected entropy change ? thank you a lot
Sunday, July 6, 2014 at 5:15am

CHEMISTRY
Find the specific heat of indium , if any one mole absorbs 23 J , when the temperature elevates from 297.5 K to 299.5 K thank you so much
Sunday, July 6, 2014 at 5:05am

chemistry
name the gas evolved when dil. Hcl reacts with sodium hydrogen cabonate. how it is recongnised ?
Sunday, July 6, 2014 at 3:46am

chemistry step for step thank a lot
10L of hard water required 5.6g of lime for removing hardness. Hence temporary hardness in ppm of cac03. The answer 1000 I think ppm= 1mg/1L 10L x 100g/mol cac03 = 1000 Who check it for me step by step Thank all tutors for your help. How many ml of a 0.05M kmno4 solution are ...
Saturday, July 5, 2014 at 8:56pm

chemistry
during an effusion experiment, oxygen gas passed through a tiny hole 2.5 times faster than the same number of moles in another gas under the same conditions. What is the molar mass of the unknown gas?
Saturday, July 5, 2014 at 4:04pm

Chemistry
A solution of ethanol has a concentration of 4.613 mol/L at 20ºC. The density of the solution is 0.9667 g m/L.. Calculate the molality of the solution..please show the solution..thanks a lot
Saturday, July 5, 2014 at 3:58pm

Chemistry
Commercial hydrobromic acid can be purchased as 40.0 % by mass 9f HBr. The density of this acid is 1.38 g m/L. Calculate the molality of this commercial acid..please show me the solution..thanks
Saturday, July 5, 2014 at 3:55pm

Soil Chemistry
Gasoline producers add oxygenated chemical compounds to reduce the amount of carbon monoxide produced when the fuel is burned. Methyl t-butyl ether (MTBE) is one such oxygenate that is no longer used because of health and environmental concerns. what are the correct exponents ...
Saturday, July 5, 2014 at 3:35pm

Chemistry
Concentrated hydrochloric acid has a purity of 36.0% by mass. The density of the concentrated of the acid is 1.19 g/mL.Determine the molar concentration of this acid..please show me the solution...
Saturday, July 5, 2014 at 3:13pm

Soil Chemistry
Global temperatures are increasing and this increase is probably due to increasing concentrations of greenhouse gases present in A) the troposphere which absorbs outgoing IR radiation B) the stratosphere which absorbs outgoing IR radiation C) the troposphere which absorbs ...
Saturday, July 5, 2014 at 12:20pm

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