1. Chemistry

    3.50 g of NH4Cl is added to 18.8 g of water. Calculate the molality of the solution.
  2. chemistry

    8.90 g of NH4Cl is added to 19.7 g of water. Calculate the molality of the solution
  3. Chemistry

    5.70 g of NH4Cl is added to 13.3 g of water. Calculate the molality of the solution.
  4. Chem

    4.30 grams of NH4Cl is added to 14.5 grams of water. Calculate the molality of the solution
  5. Chem help!!

    A rock salt (NaCl), ice, and water mixutre is used to make homemade ice cream. How many grams of rock salt must be added to lower the freezing point 10.0 degrees C? I have no idea what to do, please help! delta T = Kf*i*m delta T = 10. Kf is the molal
  6. Chemistry

    Another Equilibrium Question! The following reaction is at equilibrium in a closed 20.0-L container. At equilibrium, the pressures of NH3 and HCl are both equal to 0.00552 atm, and the mass of NH4Cl (s) is 35.4 g. Calculate the equilibrium pressure of NH3
  7. Biology

    3grams of ammonium chloride has been added to 20mL of water. The initial temperature of the solutionis 18.0 degrees, and once the ammonium is added to the water, the temperature declines to 11 degrees. Given the following information, calculate the
  8. CHemistry....Please double check DrBobb

    What mass of ethylene glycol C2H6O2, the main component of antifreeze, must be added to 10.0 L water to produce a solution for use in a car's radiator that freezes at -23C? Assume density for water is exactly 1g/mL. First we find out the freezing point:
  9. chemistry

    Assuming reaction goes to completion, determine the final concentration of NH4Cl in the calorimeter. heat capacity =3.03J/g.c density =1.012 5g of NH4Cl used 100 mL of water used NH4Cl(s) + H2O(l) --> NH4Cl(aq)
  10. AP Chem

    Calculate the pH after 0.010 mol gaseous HCl is added to 250.0 mL of each of the following buffered solutions: a. .050 M NH3/.15 M NH4Cl b. .5 M NH3/ 1.5 M NH4Cl
  11. Chemistry

    Calculate the pH after 0.010 mol gaseous HCl is added to 250.0 mL of each of the following buffered solutions: a. .050 M NH3/.15 M NH4Cl b. .5 M NH3/ 1.5 M NH4Cl
  12. chemistry

    In a calorimetry experiment, 2.14 g of NH4Cl is dissolved in 100.0 mL of water. The temperature drops by 1.43°C. Calculate the molar heat of solution for NH4Cl.
  13. thermodynamics?

    calculate the number of grams of glycerol, C3H5(OH)3 (MW=92.1 g/mol), that must be dissolved in 520 grams of water to raise the boiling point to 102.00 degrees Celsius. this whole chapter really lost me. delta T = Kb*molality delta T = 2 degrees. Kb =
  14. College Chemistry

    A 0.05 molal aqueous solution boils at 373.102 K. What is the salt in question? a. AlCl3 b. NaHSO3 c. MgCl2 d. NH4Cl e. NaCl I guessed NH4Cl and got 3 points off. I used the formula delta T=K boiling point X molality
  15. Chemistry

    What is the molality of a glucose solution prepared by dissolving 18.0g of glucose, C6H12O6 in 125g of water? A)0.000794 B)0.144 C)0.699 D)0.794 Molality is the number of moles of solute per kilogram of solvent. Because the density of water at 25°C is
  16. plz..chemistry help

    One mole of solid NH4Cl (s) isvheated in a closed box to decompose it partially according to the following reaction:  NH4Cl (s) NH3 (g) +HCl (g)  A) calculate Kp of the above system at the temperature of the experiment if the partial pressure of ammonia
  17. chemistry

    One mole of solid NH4Cl (s) isvheated in a closed box to decompose it partially according to the following reaction: NH4Cl (s) NH3 (g) +HCl (g) A) calculate Kp of the above system at the temperature of the experiment if the partial pressure of ammonia at
  18. Chemistry

    An aqueous solution is 8.50% ammonium chloride, NH4Cl, by mass. The density of the solution is 1.024g/mL. Calculate the molality, mole fraction, and molarity of NH4Cl in the solution. I know the formulas needed but I'm not sure where to start. M = moles
  19. Chemistry

    I've got a similar question as a previous student. What is a minimum volume (in gallons) of ethylene glycol (CH2OHCH2OH, an antifreeze) that has to be added to 3.00 gal of water if you desire this engine cooling solution (for a auto radiator) NOT to be
  20. chem(freezing point)

    please help! I am lost! Question: Find the expected freezing point of a water solution that contains 286g of aluminum nitrate (Al(NO3)3) in 8.5 kg of water. answer in celcius Note the correct spelling of Celsius. delta T = i*Kf*m Determine the molality of
  21. Chemistry

    a solution of 0.2113 g of water dissolv ed in 25g of a solvent freezes at 11.5 degrees celcius below the freezing point of the solvent. what is the Kf for the solvent? A)0.735 B)1.36 c)5.39 D)24.5 Help!!! delta T = Kf*molality Calculate molality = #mols
  22. Chemistry

    A solution is 0.10M in aqueous NH3. Calculate (a) the number of moles and (b) the number of grams of NH4Cl that must be added to 500mL of this solution to prepare a buffer solution with pH=9.15. You may neglect the volume change due to addition of solid
  23. Physical Chemistry

    Calculate the concentrations of each of the following solutions. (a) the molality of chloride ions in an aqueous solution of iron(III) chloride for which xFeCl3 is 0.0195 (b) the molality of hydroxide ions in a solution prepared from 9.16 g of barium
  24. Chemistry

    If some NH4Cl is added to an aqeous solution of NH3: A. pH of solution will decrease B. PH will not change C. pH will increase D. NH4Cl cannot be added to NH3 E. The solution will not have pH I think the answer is B, because if NH4Cl is added to the
  25. Chemistry

    How many grams of dry NH4Cl need to be added to 2.10L of a 0.600M solution of ammonia,NH3 , to prepare a buffer solution that has a pH of 9.00? Kb for ammonia is 1.8x10^-5. I just wanted to make sure I dd this write, can you please check my work? Thank
  26. chemistry

    When a certain amount of MgF2 is added to water, the freezing point lowers by 3.5 oC. What was the molality of the magnesium fluoride? (Kf for water = 1.86 oC/m)
  27. chemistry

    10g of nacl were added to 10ml of water. the resulting solution was diluted to be a final volume of 250ml. Given the density of the solution is 0.9864g/ml. Calculate the molality of the solution. Who helps
  28. Chem

    Some ethylene glycol, HOCH2CH2OH, is added to your car's cooling system along with 4.4 kg of water. If the freezing point of the water-glycol solution is -15.0°C, how many grams of HOCH2CH2OH must have been added? I used the equation: 15 celcius = 1 x
  29. Chemistry

    Which of the following would involve the largest production of heat per mole? a)the burning of gasoline b)the evaporation of water c)the fission of uranium d)the freezing of water e)the rusting of iron Is it C) Which of the following would involve the
  30. chemistry

    Hi, Can anyone suggest a protocol for preparing 1 Litre ammonical solution (pH 7.8, NH4-N, 3000 mg/L) from NH4Cl and NaOH? I have worked out that I need 10.7g NH4CL and 0.45 g NaOH -is this correct? I am assuming that 1st step is to prepare 0.45 g NaoH in
  31. Chemistry

    What is the molality of the solution that results when 33.3g of C2H5OH are added to 76.7g of water?
  32. Chemistry

    Calculate the change in PH when 6 ml of 0.1 M HCl is added to 100 ml of a buffer solution that is 0.1 M in NH3 and 0.1 M in NH4Cl. And calculate the change in PH when 6 ml of 0.1 M NaOH is added to the original buffer solution.
  33. Chemistry

    Calculate the change in PH when 6 ml of 0.1 M HCl is added to 100 ml of a buffer solution that is 0.1 M in NH3 and 0.1 M in NH4Cl. And calculate the change in PH when 6 ml of 0.1 M NaOH is added to the original buffer solution.
  34. Chemistry

    A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3 with 50 mL of 0.300 NH4Cl. The pKb of NH3 is 4.74. NH3 + H2O-> NH4+ +OH- 7.50 mL of 0.125 M HCl is added to the 100 mL of the buffer solution. Calculate the concentration of NH3 and NH4Cl for
  35. chemistry

    assuming the reaction goes to completion, determine the final concentration of NH4Cl in the calorimeter. NH4Cl(s)+ H2O(l)-> NH4Cl(aq) concentration of NH4Cl is 1.00M its specific heat is 3.93 and density is g/ml. note: the exact same question was asked for
  36. chemistr

    10g of nacl were added to 10ml of water. he resulting solution was diluted to be a final volume of 250ml. Calculate the molarity of the solution. My calculation 10g/58g/mol = 0.173M 0.173M/025L =0.689M Given the density of the solution is 0.9864g/ml.
  37. Chemistry

    An aqueous solution contains 2.0 % NaCl by mass. (1) Calculate the molality (NOT molarity!) of the solution. (2) Calculate the mole fraction of the solution. I know how to solve both but the problem is missing one other compound/element. I know that
  38. Chemistry

    The solubility of NH4CL is 50g/100g of water at 50°C. How many grams of NH4CL will dissolve in 20 g of water?
  39. Chemistry

    Urea (NH2)2CO is dissolved in 100.0 g of water. The solution freezes at -0.085 degrees C. how many grams of urea were dissolved to make this solution. delta T = Kf*molality Plug in 0.085 for delta T, I assume you know Kf for water, calculate molality. Then
  40. Chemistry

    How many Kilograms of water must be added to 5.0 grams of oxalic acid (H2C2O4) to prepare a 0.40 Molality?
  41. Chemistry

    How many grams of lithium fluoride must be added to 3.5 kg of water to make a solution with a molality of 2.0 molal?
  42. Chemistry

    I did an experiment to determine the freezing point depression and then find the molecular weight of the unknown solute added to the solvent, what would be the effect on calculating the molecular weight if some cyclohexane(my solvent) evaporated while the
  43. chemistry

    You dissolved 450.0 g of sugar (C12H22O11) in 150 mL of water. The density of water is 1.00 g/mL a. calculate the molarity of the solution b. calculate the molality of the solution
  44. Chemistry

    how would I find the mass of something from the molality..... How many grams of water should be added to 25.0 g of NaCl to produce a 0.450 m solution?
  45. chemistry

    What is the molality of a sodium chloride solution if 3.5 grams of the salt is added to 998 g of water Your Answer:
  46. Chemistry

    You are assigned the following amount of CoCl2. Volume of CoCl2 assigned and used 4.84 mL Concentration of CoCl2 1.39 M To this is added... Mass of charcoal 0.23 g Volume of 15.0 M ammonia 5.3 mL Mass of ammonium chloride 1.38 g The ammonium chloride was
  47. Chemistry AP

    Calculate the pH of a 0.44 M aqueous solution of NH4Cl. Kb = 1.8 × 10−5 . I've tried used the Ka=Kw/Kb equation then used the resulting 5.5e-10 in Kw=([H+][Cl-])/[NH4Cl] , using that to get the [H+], but it isn't correct and I don't know what else to
  48. C

    A solution contains 19.0 g of NH4Cl in water and is 9.10% NH4Cl. What is the mass of water present?
  49. chemistry

    calculate the change in pH when 9.00ml of 0.100M HCl(aq) is added to 100.0mL of a buffer solution that is 0.100M in NH3(aq) and 0.100M NH4Cl(aq). ...Calculate the change in pH when 9.00,L if 0.100M NaOH(aq) is added to the original buffer solution.
  50. Chemistry

    In lab we did thermochemistry, where we are supposed to find the heats of solution, heat change of calorimeter and molar heat solution of the salt. I calculated that the calorimeter constant for the water we had was 883.194 Joules. We took 1/10 of a mole
  51. chemistry/ molarity, molality

    A solution is made by mixing 20.0 mL of C6H5CH3, d=.867g/mL, with 140.0mL of C6H6, d=.874g/mL. assuming that the volumes add upon mixing, what is the molarity? what is the molality? i know that molarity= moles/L and molality= moles sol/kg solvent... but im
  52. chemistry

    A 2.500×10−2M solution of NaCl in water is at 20.0∘C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.3mL . The density of
  53. chemistry

    A 2.500×10−2M solution of NaCl in water is at 20.0∘C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.3mL . The density of
  54. AP Chemistry

    Why would .25 molality of CaCl2 have a larger effect on the freezing point of water than .25 molality of NaCl?
  55. chemistry

    How many grams of NaCl should be added to 250 grams of water to make a 0.40 m solution? I got 19 grams. this is how I got it. first I found the mass of water = 18g then I converted that to mols 18/250 = .0072. I subtracted 0.072 - 0.40 = 0.328 I found the
  56. Chemistry Class

    What is the molality of a solution made by adding 0.145 g of sodium acetate to 119 ml water? How do I find molality?
  57. chemistry

    Calculate the molality of a 10% H3PO4 solution in water.
  58. Chemistry

    Urea (NH2)2CO is dissolved in 100.0 g of water. The solution freezes at -0.085 degrees C. how many grams of urea were dissolved to make this solution. delta T = Kf*molality Plug in 0.085 for delta T, I assume you know Kf for water, calculate molality. Then
  59. Chemistry

    Urea (NH2)2CO is dissolved in 100.0 g of water. The solution freezes at -0.085 degrees C. how many grams of urea were dissolved to make this solution. delta T = Kf*molality Plug in 0.085 for delta T, I assume you know Kf for water, calculate molality. Then
  60. Chemistry

    The vapor pressure of pure water at 85 celsius is normally 433.6 mmHg but decrease to 393.8mmHg upon addition? of an unknown amount of ammoniu chloride NH4Cl to 162.2g of water at this temperature. How many grams of ammonium chloride were added assuming
  61. Chemistry

    When 3.2 g of ammonium chloride is dissolved in 75 g of water, the temperature of the solution decreases from 22.8°C to 20.1°C. What is the energy of dissolution of NH4Cl per mole? (The molecular mass of NH4Cl = 53.49 g/mol, and the specific heat of
  62. CHEM

    am lost. I have to create a buffer using NH4CL and 0.10 M NH3. I have to chose how much of the reagent to use in order to get a concentration between 0.01 and .5 M. Then after I come up with the recipe for that I have to calculate the pH based on the
  63. chemistry

    what mass of ammonium chloride is dissolved in 100 grams water in each of the following solutions in 1.10 molal NH4Cl solution, in a solution which is 75% water by mass in solution with a mole fraction of 0.15 NH4Cl? please help me solve this problem.
  64. Chemistry

    Which of the following combinations will make a good buffer solution? 0.05 M H2CO3 + 0.05 M KHCO3 0.5 M HI + 0.5 M CsI 0.3 M NH4Cl 0.3 M NH4Cl + 0.1 M NH3 0.3 M NH4Cl + 0.1 M HCl thanks
  65. chemistry

    When 3.2 g of ammonium chloride is dissolved in 75 g of water, the temperature of the solution decreases from 22.8°C to 20.1°C. What is the energy of dissolution of NH4Cl per mole? (The molecular mass of NH4Cl = 53.49 g/mol, and the specific heat of
  66. chemistry

    Calculate the change in pH when 9.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Calculate the change in pH when 9.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution.
  67. chemistry

    Calculate the change in pH when 6.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Calculate the change in pH when 6.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution.
  68. chemistry

    Calculate the change in pH when 6.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Calculate the change in pH when 6.00 mL of 0.100 M NaOH(aq) is added to the original buffer solution.
  69. CHEMISTRY

    a) Calculate the change in pH when 4.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). b) Calculate the change in pH when 4.00 mL of 0.100 M NaOH(aq) is added to the original buffer
  70. banglur

    calculate the molality of sulfuric acid in which the mole fraction of water is .85
  71. TO DrBob222 Science

    1. with respect to ion count, why is water considered to be neutral? 2. How do the number of H+ and OH- ions compare after a.) HI is added to water? b.)KBr is added to water? c.)KOH is added to water? 3. Give the Arrhenius definitions for salts. Thanks :)
  72. TO: DrBob222 science help

    1. with respect to ion count, why is water considered to be neutral? 2. How do the number of H+ and OH- ions compare after a.) HI is added to water? b.)KBr is added to water? c.)KOH is added to water? 3. Give the Arrhenius definitions for salts.
  73. Chemistry

    Calculate the pH of 100.0 mL ofa buffer that is 0.070 M NH4CL and 0.130 M NH3 before and after the addition of 1.00 ml of 5.55 M HNO3. Before = ? After = ? I know the base is NH3 and the acid is NH4Cl!
  74. chemistry

    If you mix 50 grams of NaHCO3 in 2.0 liters of water, calculate molarity & molality
  75. chemistry

    Calculate the molality of sulphuric acid solution in which mole fraction of water is .85
  76. Chemistry

    Calculate the molality of a solution prepared by dissolving 31.6 g of Fe2O3 in 750. g of water
  77. chem

    calculate the molality of a solution of 2.34g acetic acid, HC2H3O2, in 35.0 g water
  78. CHEM

    calculate the molality of a solution formed by dissolving 27.8g of LiI in 500mL of water
  79. Chemistry

    Calculate mole solute in solution? I added an amount of an unknown sample to a solution. I found that the molality of the solution is 0.085m and there is 0.0156kg of solvent. Calculate the moles of solute present in solution? Thanks!
  80. Chemistry

    Calculate mole solute in solution? I added 0.2968g of an unknown to a solution. I found that the molality of the solution is 0.085m and there is 0.0156kg of solvent. Calculate the moles of solute present in solution? Thanks!
  81. chemistry

    calculate the molality of a solution that has 1.02kg sucrose C12H22O11 dissolved in 554g water?
  82. chem

    calculate the molality of a solution that has 1.02kg sucrose (C12H22O11), dissolved in 554g water.
  83. Chemistry

    Hi I have a question So I have to determine the final concentration of NH4Cl in a calorimeter assuming reaction goes to completion. Given Measurements are: -delta T = 9.25 degrees Celcius -Density of NH4Cl = 1.013 g/mol -capacity of NH4Cl= 3.93 J/g*C
  84. chemistry

    Calculate the change in pH when 4.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). Delta pH=? Calculate the change in pH when 4.00 mL of 0.100 M NaOH(aq) is added to the original buffer
  85. chemistry

    The freezing point of a 0.010 m aqueous solution of a nonvolatile solute is ?0.072°C. What would you expect the normal boiling point of this same solution to be? have no clue, thanks for the thelp Freezing point depression= N*kf* molality you have
  86. Chemistry

    The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.187 g sample of NH4Cl is added to 65.0 mL of water in a calorimeter at 26.5°C, what is the minimum temperature reached by the solution? [specific heat of water = 4.18 J/g°C; heat capacity
  87. chikirshu

    Q.1 0.1 mole of which of the reagents listed below[(1)to(6)]could be added to 1 litre of water to make 0.1M solutions of each of the following ions seprately? (a)NH4^+ (b)CH3COO^- (c)Cl^- (1) NH3 (2)NH4Cl (3) CH3COOH (4)CH3COONa (5)HCl (6)NaCl Q.2 Explain
  88. CHEMISTRY MOLALITY!!!!!

    A bottle of wine contains 13.1% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality. i don't know how to get molality. please help!!!! Molality is the
  89. Chem

    1) Which solution will have the lowest OH- A) Na2CO3 B) NaHCO3 C) NaCl D) NaHSO4 E) NH4Cl 2) Which solution will be the strongest base? A) Na2CO3 B) NaHCO3 C) NaCl D) NaHSO4 E) NH4Cl 3) Which aqueous solutions are acidic? A) Na2CO3 and NaHCO3 B) NaCl and
  90. Science URGENT PLEASE

    1. what would you expect the pH value for grapefruit juice to be? (>7, 7,
  91. CHEMISTRY..please help..thanks

    Calculate the new molarity if each of the following dilutions is made. Assume the volumes are additive. (a) 52.3 mL of water is added to 27.1 mL of 0.124 M KOH solution (b) 110. mL of water is added to 54.2 mL of 0.808 M NaCl solution ((please show work,
  92. physics

    An aluminum vessel with a volume capacity of 510 cm3 is filled with water to the brim at 20.0°C. The vessel and contents are heated heated to 49.9°C. During the heating process, will the water spill over the top (in this case the answer would be
  93. physics

    An aluminum vessel with a volume capacity of 530 cm3 is filled with water to the brim at 20.0°C. The vessel and contents are heated heated to 42.5°C. During the heating process, will the water spill over the top (in this case the answer would be
  94. Chemistry

    Calculate the molality of a solution prepared by dissolving 225.5 g KNO3 in 825mL of water. Show your work
  95. Chemistry

    Testing for water hardness using EDTA as a titrant: Suggest a reason why the buffer is good for only a week. The buffer contains disodiumEDTAdihydrate, MgSO47H20 and distilled water. NH4Cl and NH4OH is also added then diluted. I know that after a week, the
  96. chemistry

    calculate the equilibrium constant for the reactionas written at 940K. NH4Cl->NH3+HCl delta H= NH4Cl -1779, NH3 -46, HCl -92 delta s= NH4Cl - 682,NH3 192,HCl 187 i don't know how to solve for the equilibrium constant without the concentration of the
  97. Chemistry

    Calculate the change in pH when 5.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq). (I have several problems like this can some one work this through for me as a base line)?
  98. Chemistry

    Calculate the change in pH when 5.00 mL of 0.100 M HCl(aq) is added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq) and 0.100 M in NH4Cl(aq).
  99. Chemistry

    I have a solution that contains 30 lbs of sugar in 2.5 gallosn of water. Calculate the mass percent, molarity, molality and mole fraction
  100. Chemistry

    Hello I need help with this excersise: How many moles of NH4Cl are neccesary to add to 1 liter of solution of Co2+ 0,20 M in order to prevent the precipitation when the solution is saturated with H2S (0,1M) and the pH is 7,50. It 's known that pKbNH3=4,75