Why are alum rystals not supposed to washed in pure water?

34,492 results
  1. Chemistry

    The density of pure silver is 10.5 g/cm3 at 20 °C. If 5.25 g of pure silver pellets is added to a graduated cylinder containing 11.2 mL of water, to what volume level will the water in the cylinder rise?

  2. chemistry

    The density of pure copper is 8.96 at 20°C. If 6.50 g of pure copper pellets is added to a graduated cylinder containing 13.4 mL of water, to what volume level will the water in the cylinder rise

  3. physics2 lab

    a 50 g bracelet is suspected of being gold plated lead instead of pure gold.when it is dropped into a full glass of water,4cm of water overflows.is the bracelet pure gold?if not,what proportions of its mass is gold?determine also the amount of its

  4. Chemistry

    You would like to determine if a set of antique silverware is pure silver. The mass of a small fork was measured on a balance and found to be 80.56 g. The volume was found by dropping the fork into a graduated cylinder initially containing 10.0 mL of

  5. Chemistry Lab

    Im preparing my report for Synthesis of Alum chemistry lab. Need help with these 2 questions: 1-What other cations besides aluminum can be used to make alum crystals? Explain 2-Why we need to add sulfuric acid slowly to the solution as opposed to pouring

  6. Chemistry

    What is the freezing point of a solution made by dissolving 450 g of ethylene glycol (C2H6O2) in 550 g of water? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m.

  7. Chemistry

    Calculate the percent yield of alum if you obtained 75.0 g of potassium alum from 5.00 g Al.

  8. Chemistry

    Potash alum is a double salt. Explain this statement using the chemical formula of the alum.

  9. chem

    I had to go and do a oxidation- reduction lab where: I went oxidized borneol with sodium chloride and added 0.360g racemic borneol, 1ml acetone, and .30ml glacial acetic acid. Then I heated and added through the condenser every 4 minutes .5ml 6% sodium

  10. Environmental Science

    Which is an example of a scientific theory? A. If a person takes at least one vitamin per day, then it will reduce a person’s level of tiredness. B. Organisms evolve over time due to changes in heritable physical characteristics. C. On average, larger

  11. chemistry

    Hi, I need help figuring out this question. An impure sample of barium hydroxide, Ba(OH)2 (aq), has a mass of 0.540 g. It is dissolved in water and then treated with excess sulfuric acid, H2SO4(aq). This results in the formation of a precipitate of barium

  12. chemistry

    A piece of an aluminum can was cut into small pieces. Then 0.422 g of the chips from the can was used to prepare potassium alum according to the procedure we used. Calculate the theoretical yield (in g) of potassium alum that could be obtained in the

  13. Physical Chemistry

    Assuming that the osmotic pressure of a sample of sea water at 10 C is 25.5 atm, calculate the work required under reversible conditions at this constant temperature to prepare 9 litre of pure water from this sea water. (Take the available volume of sea

  14. Chemistry

    How would I calculate this? 30.0 mL of pure water at 280. K is mixed with 50.0 mL of pure water at 307 K. What is the final temperature of the mixture?

  15. Chemistry 102

    The Ksp for cerium iodate, Ce(IO3)3 is 3.2 e-10. What is the molar solubility of Ce ion in pure water? = .0019 M B) A 0.031 M sodium iodate is added as a common ion. What is the concentration of Ce ion with the common ion present? C) What is the ratio of

  16. Chemistry

    What is the freezing point of an aqueous 2.25 m potassium nitrate (KNO3) solution? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m.

  17. Science

    Why was the tert. Butyl chloride finally washed with water,?

  18. Chemistry

    Why are alum rystals not supposed to washed in pure water?

  19. Chemistry

    What concentration of aqueous CaCl2 solution freezes at -10.2ºC? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m. A. 5.48 m B. 11.0 m C. 1.83 m D. 6.12 m E. 2.74 m

  20. Chemistry

    Mercury(II) sulfide, HgS, is practically insoluble in pure water. Its solubility at 25 degrees C is probably no more than 3×10^−25 g/L. Of the following quantities of pure water, which is the smallest quantity that could be used to make a saturated

  21. chemistry

    Lead chloride dissolves in water according to PbCl2(s)↔Pb2++2Cl−(aq) The solubility in pure water has been measured to be 4.44 g⋅L−1. Calculate the solubility product of lead chloride in pure water. Your answer should be in units of molarity raised

  22. chemistry ap

    Why would [23.8-(.0588)(23.8)] be the proper setup to determine the vapor pressure of a solution at 25 Celsius that has 45g of C6H12O6, glucose (MM=180gxmol^-1), dissolved in 72g of H2O? The vapor pressure of pure water at 25Celsius is 23.8 torr. vp pure

  23. Chemistry

    A compound Y containg C, H and O only was burnt in a strem of pure oxygen.The carbon(iv)oxide and water produced were collected in pure weighed reading obtained are initial mass of Y=20.63mg mass of CO2 product=57.94mg mass of water=11.85mg.What is the

  24. chm

    How would you classify the following material?swimming pool water homogeneous mixture

  25. AP Chemistry

    1. If alum is heated at first too strongly causing it to splatter out of the crucible what effect will this have on the determination of the water hydration? 2. If alum is heated insufficiently what effect will this have on the determination of the water

  26. Chemistry

    Alum is a hydrated compound containing 45.5% water. How many moles of water are contained in one mole of this hydrate. Data for alum M= 474 g∙mol-1

  27. Environmental Science

    What is the purpose of adding alum to water during the water treatment process? a.to filter and remove large organisms and trash b.to form flocs that bacteria and other impurities will cling to c.to prevent bacterial growth d.to remove unwanted gases I

  28. Chemistry lab

    1)Why is it necessary to heat the alum until its mass does not change by more than 2mg? 2)Why its it necessary to store the alum in a disccator while it cools before measuring the mass? ( systhesis and analysis of alum crystals experiment)

  29. University Chemistry (first year)

    I'm working on a first year chemistry lab where we synthesized alum from alunimini foil and I'm doing the report and one of the questions is as follows: Based on your findings, what volume of water can be cleared of suspended solids by one beverage can

  30. Chemistry

    What would be the pH of a soda water made by saturating pure water with pure CO2 at 1 atm pressure?

  31. Chemistry

    When doing a simple distillation of ethanol-water, is the vapor pure ethanol or does it also contain water? (knowing that ethanol has lower boiling point than water) If it is not pure ethanol, why is it not possible to separate water & ethanol completely?

  32. Organic Chem I Lab

    I had to react 1-propanol with NaBr and H2SO4. I refluxed for one hour and when attempting to separate out the product (product was supposed to be 1-bromopropane) via sep funnel either could no longer distinguish between the organis layer and the aqueous

  33. Chem

    I'm confused with Determining the concentration of a soution: beer's law lab. 1.Explain why pure water is set for a transmittance of 100%. - I believe the pure water is set for a transmittance of 100% in order to for a tranmission relative to water 2.

  34. Chemistry

    Co-precipitation is the process by which undesirable materials are "carried down" and trapped on the suface or within the desired precitate. The precipitate is washed with distilled water to remove the co-precipitates which are more soluble that the

  35. chemistry

    Co-precipitation is the process by which undesirable materials are "carried down" and trapped on the suface or within the desired precitate. The precipitate is washed with distilled water to remove the co-precipitates which are more soluble that the

  36. Chemistry

    What is the freezing point of an aqueous 2.25 m potassium nitrate (KNO3) solution? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m.

  37. Chemistry

    Question: When 1.97 grams of Pb(OH)2(s) is added to 1.00 liter of pure water at 25 C a saturated solution (some solid is present) is formed that has a pH of 8.97. Compute the Ksp value for Pb(OH)2 using the data. How do i go about getting the Molarity from

  38. chemistry

    Which of the following is true? A. HF does not ionize in water to any extent. B. All are true C. HF ionizes equally in a solution of KCl as in pure water. D. HF ionizes more in a solution of NaF than in pure water.

  39. Physical Chemistry

    The measured osmotic pressure of seawater is 25 atm at 273K. a.) What is the activity of water in seawater at 273 K? Take the partial molar volume of water in seawater to be 0.018 M-1. b.) The vapor pressure of pure water at 273 K is 4.6 torr. What is the

  40. PLEASE HELP! PHYSICAL CHEM

    The measured osmotic pressure of seawater is 25 atm at 273K. a.) What is the activity of water in seawater at 273 K? Take the partial molar volume of water in seawater to be 0.018 M-1. b.) The vapor pressure of pure water at 273 K is 4.6 torr. What is the

  41. Chemistry

    At room temperature, ethanol's density is 0.789 g/mL while water's density is 0.997 g/mL. When a few milliliters of ethanol are added to water, the two liquids mix. A student is given a unknown liquid at room temperature and experimentally determines its

  42. Chemistry

    I had a 1.094g of mystery Alum. "AB(SO4)c. dH2O" (I assume that that the Alum is KAl(SO4)2-12H2O but we don't know A B c or d, we do know that mass percent of water is 51.9) After processing the alum (Ba(NO3)2 and HNO3 through a gooch crucible) we end up

  43. Chemistry

    How would I find the percent of water lost in alum after it has dried for a week? Wet Alum = 13.44g Dry Alum = 11.28g

  44. chemisty

    what will be the mass of angydrous Alum left over if one starts with 100.00 g of hydrated Alum? please can you explain what fraction do I need to use. Based on the given information I can find the %theoretical of water in angydrous Alum. But I still don't

  45. chemistry

    Why is it wise to clean the aluminum? Why is the reaction done in the hood? Why must suspended solids be removed from the basic solution? Why is an ethanol-water mixture, rather than pure water, used to wash the collected alum?

  46. chem

    What do question about Aluminum, hand this is some general question about it can someone help me to answer them Why is it wise to clean the aluminum? Why is the reaction done in the hood? Why must suspended solids be removed from the basic solution? Why is

  47. chemistry

    Porassium alum is 3.9 parts per 100 parts of water. Knowing this, how many moles of potassium alum are present in 50ml?

  48. chem/science

    A piece of an aluminum can was cut into small pieces. Then 0.422 g of the chips from the can was used to prepare potassium alum according to the procedure we used. Calculate the theoretical yield (in g) of potassium alum that could be obtained in the

  49. Chem Problem

    I need help solving this question, I have no idea what I'm supposed to do. What is the minimum pressure in kPa that must be applied at 25 °C to obtain pure water by reverse osmosis from water that is 0.165 M in sodium chloride and 0.029 M in magnesium

  50. Chem Problem

    I need help solving this question, I have no idea what I'm supposed to do. What is the minimum pressure in kPa that must be applied at 25 °C to obtain pure water by reverse osmosis from water that is 0.165 M in sodium chloride and 0.029 M in magnesium

  51. Chemistry

    Potash alum is adouble salt . Explain this statement using the chemical formula of the alum

  52. chemistry

    what will be the mass of angydrous Alum left over if one starts with 100.00 g of hydrated Alum?

  53. Chemistry 211

    Which of the following statements is a reasonable explanation for why a percent yield may be less than 100% for the synthesis of the alum, select all that apply. a) The aluminium foil did not completely react b) Some alum sample remained in the beaker and

  54. Chemistry

    I conducted the synthesis of an Alum experiment in my lab last week and I'm working on my report. I'm almost done expect I don't know how one could increase the yield of the product (alum crystal)? And also what is the point of adding sulfuric acid? Can

  55. Definitions....

    What is pure liquid? What is impure liquid? Thx You are going to have to define these in context. "Pure" is a relative term. For instance, the term "pure" water...is it really pure? It depends on the definition of pure being used. Pure liquid could mean

  56. chemistry

    calculate the ph of a solution by addition of 0.1 mL of 0.5m hcl to 50.0 ml pure water. I'm supposed to use c1v1=c2v2... but I did 0.1/50ml=0.002.... 0.002x0.5.. then -log the answer and got 3 for a ph is it right?

  57. Chemistry

    The calcium in a 150 mL sample of water from the Ogeechee River at a location near Savannah was determined by precipitating Ca2+ as CaC2O4.H2O (FW=146.115 g/mol). The precipitate was collected by filtration, washed and then ignited [turning the CaC2O4.H2O

  58. Chemistry

    Mass of aluminum sample = 0.97g Mass of watch glass = 32.1851g Mass of watch glass & sample = 45.2550g a) What is the mass of alum produced? b) What is the theoretical yield of alum? c) What is the percent yield? d) What is the molecular mass of alum?

  59. Chemistry

    Mass of aluminum sample = 0.97g Mass of watch glass = 32.1851g Mass of watch glass & sample = 45.2550g a) What is the mass of alum produced? b) What is the theoretical yield of alum? c) What is the percent yield? d) What is the molecular mass of alum?

  60. science

    which has a lower ph pure water that is hot or pure water that is cold? is it possible for water to be neutralbut have a ph less than or greater than 7.0? how readily an acid donates a hydrogen is a fuction of how well the acid is able to accomodate the

  61. Chemistry

    I need to calculate the redox potential for the following: 1/2 O2 + 2H+ + 2e- H2O I'm using the formula E = E'_0 + RT\nF ln ([electron acceptor]/[electron donor]) The electron acceptor is H+, so I can use the concentration of that which is indicated by the

  62. chemistry

    What concentration of aqueous CaCl2 solution freezes at -10.2ºC? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m.

  63. Chemistry

    The ion-product of pure water, Kw, is 2.51 * 10(-14) at the body temp of 37 degrees Celcius. What are the molar H2O and OH concentrations in the pure water temperature?

  64. chemistry

    Pure water has a density of 1.00 g/ml at 297 . Calculate the molar concentration of pure water at this temperature. Would i just convert grams to moles, and ml to liters?

  65. Math

    Jose washed 3/10 of the windows on his house Saturday morning. He washed another 3/5 of the windows that afternoon. What fractional parts of the windows are not washed 3/10?

  66. chemistry

    I need to take a sample of the following substances: *an aromatic compound *a liquid that has Alum in it *a volatile liquid *something with a ketone group in it *something with an alcohol group in it *something with an ester group on it and 15 more

  67. Chemistry

    Can someone clarify where I'm going wrong with this? Kw for pure water is 1.2 x 10-15 at 5°C. The pH of pure water at 5°C? I thought Kw=[H3O][OH]... I've tried a few different things, but none seem to work. Thanks!

  68. science

    what is the solubility of alum in 100 ml of water at 20 degrees celcius?

  69. Chemistry Intro

    If the solubility of alum is 1g @ 1 degree celcius and 1.7 g at 6 degree celcius how much alum (KAl(SO4)2.12H20) would you expect to dissolve at 5.5% C?

  70. science

    Calculate the hydroxide ion concentration of pure water. Use the fact that the pH of pure (neutral) water is 7.00. The look up the definition of pH. You can also get it from the dissociation costant of the H2O -> H+ + OH- reaction. To review that, see

  71. Organic Chemistry

    In order to obtain pure synthetic plant hormone, a 2:1 mixture of water and ethanol is used as the crystallizing solvent. Why is a solvent mixture used? A. Organic compounds are not soluble in pure ethanol. B. Ethanol and water have similar boiling points,

  72. chemistry

    Lead chloride dissolves in water according to PbCl2(s)↔Pb2++2Cl−(aq) The solubility in pure water has been measured to be 4.44 g⋅L−1. Calculate the solubility product of lead chloride in pure water. Your answer should be in units of molarity raised

  73. Chemistry

    Lead chloride dissolves in water according to PbCl2(s)↔Pb2++2Cl−(aq) The solubility in pure water has been measured to be 4.44 g⋅L−1. Calculate the solubility product of lead chloride in pure water. Your answer should be in units of molarity raised

  74. chemistry

    If not all the alum dissolves in the water before adding the Ba(NO3)2 solution, what effect will this have on the sulfate percent error determination?

  75. Chem

    If not all the alum dissolves in the water before adding the Ba(NO3)2 solution, what effect will this have on the sulfate percent error determination?

  76. Chemistry

    Co-precipitation is the process by which undesirable materials are "carried down" and trapped on the suface or within the desired precitate. The precipitate is washed with distilled water to remove the co-precipitates which are more soluble that the

  77. Chemistry

    What does it mean if the percent of sulfate in a sample of alum is greater that the theoretical percent of sulfate in alum?

  78. Chemistry

    A reaction requires 0.5 g of pure methyl oleate (density = 0.87g/mL) (MW = 310g/mol). How many mL of 70% pure methyl oleate are needed for the reaction. I don't exactly know how to start this off. I think what I'm supposed to do is multiply the 70% by the

  79. Chemistry

    If there were two solutions- one with areagent(100% pure) mixed in water and the other solution containing the same reagent (99.9% pure) mixed in equal volume of water. How significant would the difference in concentration be between these two solutions?

  80. physics

    15g iron (c=450 J/kg K) bolt is heated from 21 C to 312 C. It is then plunged into a 2kg of 15 C water (c= 4180 J/kg K) into a 4.6kg alum. tub (c=903 J/kg K) What is the final temp. (Tf) of the water and the tub? for some reason..., i got 0.472 C for final

  81. Chemistry

    What is the freezing point of an aqueous 2.65 m calcium chloride (CaCl2) solution? The freezing point of pure water is 0.0ºC and Kf of pure water is -1.86ºC/m.

  82. chemistry

    using leChatlier's principle, which of following is more or less soluble in following solutions than in pure water. and explaination for each asked for. Compared to pure water are they less, more or same? thanks. AgBr in 0.100M HBr AgBr IN 0.100 m HNO3

  83. College Chemistry I

    A method for recycling scrap aluminum converts it to alum [potassium aluminum sulfate dodecahydrate, KAl(SO4)2·12H2O]. What is the maximum amount of alum (in metric tons) that can be prepared from 3.12 metric tons of scrap aluminum (1 metric ton = 1000

  84. ochem

    Can you suggest some possible reasons for using a mixture of water and ethanol (1:1 mixture H2O/EtOH) as crystallizing solvent rather than using either pure ethanol or pure water?

  85. Chemistry

    Regarding conductivity: 1. If a solution has a high conductivity, it indicates that there are a lot of __________________ in solution. [Answer: ions] 2. Pure acetic acid does not conduct electricity, nor does pure water, but a mixture of the two does

  86. chemistry

    I had this on a test, not sure how to do it Explain, using balanced chemical reactions with the smallest integer coefficients, why each of following occurs. a. CuI2 (insoluble in pure water) dissolves readily in aqueous ammonia, HN3(aq) b. AgBr (insoluble

  87. chemistry

    Water in contact with air is acidic due to the dissolved carbon dioxide. Water in equilibrium with the air contains 4.4 x 10^-6% CO2. The resulting carbonic acid, H2CO3,gives the solution a hydrogen ion concentration of 2.0 x 10^-6M, about 20 times larger

  88. science

    why was tert.butyl washed with water

  89. Microbiology

    You need 3.5L of 50mM NaCl from your 20X stock. How would you accomplish this: 20X stock __________ml Pure Water ___________ml From whatever number I plugged in trying to solve it, I got: 175ml of 20X stock and 3,430ml of Pure Water. Have no idea if those

  90. CHEM HELP

    The partial pressure of water above a solution of water and a nonvolatile solute at 25oC is 19.2 mm Hg. What is the mole fraction of the solute please help....I really don't know how I am supposed to solve this question. I know that Partial pressure of the

  91. Chemistry

    I am very confused with this problem, i tried using the percent yeild but i got stuck. Can u help? The O'Keefe's have 75 gallons of cucumbers for pickling. The 1.5 M KOH solution costs $3.50 per liter, 9 M H2SO4 solution costs $8 per liter, and ethanol

  92. organic chemistry

    why was the tertiary butyl chloride was washed with water?

  93. SCIENCE

    (aq) means the solution is dissolved in water used as a solvent. (l) means the COMPOUND (not element, usually) is a pure liquid. (g) means gas and (s) means solid. In the equation below, HCl(aq) + NaOH(aq) -->NaCl(aq) + H2O(l)This means that an aqueous

  94. Physical chemistry

    Estimate the vapor pressure of sea water at 20C given that the vapor pressure of pure water is 2.338 kPa at that temperature and the solute is largely Na+ and Cl- ions, each present in about .50 mol/dm^3. I'm pretty sure the formula to use is pj=xjpj'.

  95. chemestry

    why was the tert .butyl chloride finally washed with water?

  96. Science

    Why was the tert butyl chloride finally washed with water?

  97. science

    why was the tert.butyl chloride finally washed with water?

  98. Chemistry

    Why was tert butyl chloride finally washed with water?

  99. chemistry

    why was the tertiary butyl chloride finally washed with water?

  100. UPNG

    Why was the tert. butyl chloride finally washed with water?

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