1. math

    I am helping my child with this. Can you show me how to Solve word problems by writing an equation with a variable to represent the given information and then solve the equatin.

    asked by prscilla on April 13, 2007
  2. math

    If 10 points are arranged on a circle, how many lines are needed to join every point to every other point once? First solve simpler problems to determine a pattern.

    asked by Anonymous on April 16, 2012
  3. Health and Human Services

    I am having problems looking for a definition of data relevancy and data accessibility related to the field of health care. Can someone help me find any information regarding these definitions.

    asked by Lynn on January 25, 2010
  4. Science-PHYSICS

    The metre was originally defined as a fraction of the distance from the North Pole to the equator. What problems would this definition of the metre create for people?

    asked by Anonymous on November 7, 2010
  5. Life orientation

    Provide recommendations on how human problems on the community and name 2institutions or community organisations that are involved in supportingm or giving redress to these disaster

    asked by Agnes on April 8, 2011
  6. english

    I am having some serious problems with parallelism. I do not understand how to use parallelism. I've read the lesson in my textbook and I've looked at different websites that help explain it, but I just can't get it. Can anyone break this down in "layman's

    asked by Andy on February 18, 2011
  7. algebra

    x^2+3x-12=0 I need to factor this and thought I knew how, but I can't figure this one out. Factors of 12 are 1,12; 2,6; 3,4 and when I subtract these I don't get the 3 I need for the 3x. Am I overlooking something? My other problems were easy, so I don't

    asked by meg on November 15, 2010
  8. PreCalculus II

    perform the indicated operation (3sinx-2)(sinx+1) I need someone who can help me to understand what I am supposed to be doing with this problem, a step by step would be increasingly helpful so that I can apply it to other problems like this.

    asked by Amber Lance on January 30, 2013
  9. Political Science

    I need some good examples of topics to write a 5page paper on. The paper is to address any MAJOR problems of the American national government. Thank you

    asked by Mel on November 24, 2009
  10. Bobpursley can you help me with my problems below?

    I had problems from yesterday but I still don't get them can you help?do you want me to repost? repost: I cant find them.

    asked by Margie on March 4, 2007
  11. Algebra

    Checking two problems : 1. x^2-7x+12 / x^2-16 = (x-3)(x-4) / (x-4)(x+4) (x-4) cancels out Answer (x-3)/(x+4) 2. x^2-3x+2/7x-14 divide by x^2-1/7x+7 x^2-3x+2/7x-14 * 7x+7/x^2-1 (x-1)(x-2)7(x+1)/7(x-2)(x-1)(x+1) To me it looks like everything cancels out, is

    asked by John on November 6, 2007
  12. Algebra

    show me step by step how to solve t hese problems. 5 7/8 +(3 1/3 - 1 1/2) i cannot get this down please help

    asked by Sharon on October 15, 2013
  13. math

    how do you solve these problems? 1.2x/3 + 1/3 - x/8= 2/3 2. 3n + 9/10 + n/5= -2 3/10 3. 3k/4 - 28 - 2k/3 = 37 thank you can you please show me step by step how you got the answer?

    asked by Sara! on June 3, 2010
  14. Algebra

    Can someone help me factor: 4u^3+3u^2-9u+2 I don’t understand how to factor 4 terms problems.

    asked by P on March 28, 2019
  15. Math-Fractions

    How would I solve these two problems. (We have to simplify our answer) 5/7 divided by 8/21 12/7 divided by 9/21

    asked by Joe on January 19, 2010
  16. Math

    How do I find (a) f*g (b) g*f (c) f*f of these problems? If you can, please show me step by step ^___^ thank you 1)f(x)=x^2 2) f(x)=3x+5

    asked by Sira on September 30, 2012
  17. Geometry B: Unit 3: Similarity Lesson5 Practice

    If you have done this please help me with just the practice question I have already done the quiz I just need help with the practice problems because they are in more detail.

    asked by Blair on March 4, 2016
  18. life orientation

    what are the problems that the community faced? what did the community members do before the protest?

    asked by Anonymous on June 2, 2015
  19. algebra 1b

    i need to know how to solve certain problems like this 4x=2y-10 x+2y=5 i need examples of this and shown to me step by step

    asked by erica on March 21, 2009
  20. algebra NEED HELP

    I've tried to do these problems multiple times and I'm just so confused. 1. (root x-5) + 5 = 0 2. (root 2-7x) = 2x Thanks!

    asked by Liz on April 29, 2015
  21. A question

    in the the theories of aggression what is something you could take and use with the people in your life who have problems with aggression?

    asked by Bryan on April 22, 2009
  22. pre algebra

    How do I figure out problems like 52 = p +(-41)? I tried doing the steps but I got -11, which is wrong. Can someone walk me through the steps?

    asked by john on November 13, 2009
  23. Chemistry

    An impure sample of (COOH)2 · 2 H2O that has a mass of 2.9 g was dissolved in water and titrated with standard NaOH solution. The titration required 32.4 mL of 0.144 mo- lar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample.

    asked by Bella on April 1, 2016
  24. Chemistry

    One half-cell in a voltaic cell is constructed from a silver wire electrode in a .25 M solution of AgNO3 . The other half-cell consists of a zinc electrode in a .001 M solution of Zn(NO3)2. Calculate the cell potential I have no idea and am so stressed,

    asked by Anonymous on November 18, 2015
  25. Algebra-Please check my calculations

    Could you please check my answers and help with the ones I can't figure out- 1. Solution to the radical function sqrt(1/2x+1) = 1 is x = 0 True or False I think it is true according to my calculations 2.Solve x = sqrt(8x) 8x = x^2 x^2 - 8x = 0 x(x-8) = 0 x

    asked by JayLynne-I had misprint in previous posting on October 19, 2010
  26. pre-calculus

    solve the logarithmic equation. be sure to reject any value of x that is not in the domain of the orginal logarithmic expression. In square root of x+2=2 (If I try to make the square root sign it will not come out right so I wrote it out instead) What is

    asked by ladybug on October 6, 2012
  27. chem

    A student mixes 5 mL of 2.00 x 10^-3 M Fe(NO3)3 with 5 mL 2.00 x 10 ^-3 M KSCN. They find that in the equilibrium mixture concentration of FeSCN^2+ is 1.40 x 10^-4 M. Find each of the following: the initial concentration in solution for Fe^3+ and SCN, the

    asked by Grant on October 14, 2015
  28. Chemistry

    In the following experiment, a coffee-cup calorimeter containing 100 \rm mL of \rm H_2O is used. The initial temperature of the calorimeter is 23.0 \rm ^{\circ}C. If 9.80 g of \rm CaCl_2 is added to the calorimeter, what will be the final temperature of

    asked by Ali on June 17, 2012
  29. College Chemistry

    Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are colorless. When a solution of C is mixed with

    asked by Lisa on November 10, 2010
  30. Solutions

    When adding 100mL of water to a solution of 50grams of KI in 400mL of water, the total amount of KI in the new solution will be how many grams? Did I miss something here? The total amount of KI, if no extra is added and none taken away, MUST be 50 grams?

    asked by Kellie on February 25, 2007
  31. Qualitative analysis ( Chemistry)

    A solution x forms a white precipitate with dilute sulfur in acid and also with aqueous silver nitrate. What could solution x contain? A) Barium Chloride B) Barium nitrate C) Magnesium chloride D) Magnesium chlorine Could someone tell me how to get the

    asked by Cheezel on November 17, 2016
  32. Chemistry

    When 23.6 of calcium chloirde CaCl2 was dissolved in water in a calorimeter, the temperature rose from 25.0 degrees C to 21.56 degrees C. If the heat capacity of the solution and the calorimeter is 1071 J/ degrees C, what is the enthalpy change when 1 mol

    asked by Lauren on November 1, 2007
  33. chemistry

    an unsaturated solution is made by completely dissolving 20.0 grams of NaNO3 in 100.0 grams of water at 20.0 degrees celcius. show a corrct numerical sat up for calculating the number of moles of nano3(gram-formula mass = 85.0 grams per mole) used to make

    asked by nicole on April 23, 2012
  34. Chemistry

    Balance the following equation for a half reaction that occurs in acidic solution. Use e– as the symbol for an electron. U^4+ --> UO2^+ There is a hint: In acidic solution, you may add H2O and H as needed to balance oxygen and hydrogen. When finished,

    asked by Clueless on April 28, 2014
  35. Chemistry/pH- Weak Acid

    Hi again! I have a new question, Can you help me? Consider 50.0 mL of a solution of a weak acid HA (Ka = 1.00.E-6), which has a pH of 4.000. What volume of water must be added to make the pH = 5.000? My Calculations: To calculate the concentration of x, I

    asked by Mary on August 17, 2008
  36. college Chemistry

    A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?

    asked by Ivy on December 6, 2010
  37. mixture

    Sugar solution is composed of 40 grams of sugar and 200 grams of water. How many grams of sugar must be added to make a 60% sugar solution? (Kindly write the equation..... tnx)

    asked by HELP HELP MNHS on November 22, 2012
  38. Chemistry

    A reference solution is to be prepared with 5 PPM parabenzopyrene (molecular weight = 252). The quantity of parabenzopyrene required for preparing one litre 5 PPM solution is (A) 252 mg (B) 25.2 mg (C) 5 mg (D) 252 g

    asked by rohit on June 25, 2013
  39. Chemistry Help Pls!!!

    A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?

    asked by Jerome on December 6, 2010
  40. college Chemistry

    A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?

    asked by Ivy on December 7, 2010
  41. Chemistry

    What initial concentration of Cd2+ is required to result in a cell potential of 0.200 V in a voltaic cell constructed by connecting a nickel electrode that is dipped into 1.00 M NiSO4 solution to a cadmium electrode that is dipped into a solution

    asked by Richard Swasley on April 2, 2017
  42. Chemistry

    When an aqueous solution of sodium hydroxide, NaOH, is added to an aqueous solution of chromium(III) nitrate, Cr(NO3)3, a precipitate of chromium(III) hydroxide, Cr(OH)3, forms. Write a balanced net ionic equation for this reaction.

    asked by Tina on March 1, 2016
  43. chem

    An impure sample of (COOH)2 · 2 H2O that has a mass of 4.3 g was dissolved in water and titrated with standard NaOH solution. The titration required 44.5 mL of 0.11 mo- lar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample. Answer in

    asked by Big Boy on April 4, 2019
  44. chemistry

    In the following experiment, a coffee-cup calorimeter containing 100ml of H2O is used. The initial temperature of the calorimeter is 23 degrees celcius. If 7.20g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution in

    asked by kayla on October 3, 2008
  45. chemistry

    An ideal liquid solution has two volatile components. In the vapor in equilibrium with the solution, the mole fractions of the components are (a) both 0.50; (b) equal, but not necessarily 0.50; (c) not very likely to be equal; (d) 1.00 for the solvent and

    asked by anonymous on February 20, 2010
  46. Chemistry

    Suppose you have 5.00g of powdered magnesium metal, 1.00L of 2.00M potassium nitrate solution, and 1.00L of a 2.00M silver nitrate solution. a) Which one of the solutions will react with the magnesium powder? I don't understand how to go about answering

    asked by Feufolia on February 22, 2016
  47. CHEMISTRY !!! HELP !

    Calculate the pH of the solution after the addition of the following amounts of 0.0617 M HNO3 to a 70.0 mL solution of 0.0750 M aziridine. The pKa of aziridinium is 8.04. 1)Volume of HNO3 equal to the equivalence point 2)89.5mL of HNO3 I got pH= 7.37 for 1

    asked by Owen on September 26, 2015
  48. Chemistry

    Consider the reaction: M + 2HCl ¨ MCl2 + H2 When 0.85 mol of the metal, M, reacted with an aqueous HCl solution (the HCl is in excess), the temperature of the solution rose because the reaction produced 6795 J of heat. What is ∆H in kJ per mol of M

    asked by Jessica on May 4, 2015
  49. Biology

    A stock protein sample that has a concentration of 250.0mg/ml. You need to dilute this sample to 20.0 mg/ml in buffer. The final volume of the diluted solution is 5.0ml. how much of the stock protein solution and buffer are required to achieve this? Answer

    asked by Matthew on October 12, 2017
  50. chemistry

    a large 1.5 x 10^6liter tank contains water polluted with lead (II) nitrate at a molarity concentraion of 2.5 x 10^-6 M to the tank, you add 59.7 liters of 0.075 M potasium chloride solution. did you add enough potassium chloride to remove all the lead(II)

    asked by tom on February 26, 2012
  51. Chemistry

    Can someone please explain this problem to me step by step pleaseeeeeee? In the following acid—base neutralization reaction HNO3 (aq)+ KOH (aq)---KNO3(aq) + H2O(I) What is the molarity (M) of an HNO3 solution if 50.0ml is needed to react with 25.0ml of

    asked by Tasha on October 23, 2012
  52. math

    How many quarts of water must be added to 18 quarts of a 32% alcohol solution to dilute it to a solution that is only 12% alcohol.

    asked by john on July 30, 2014
  53. chem

    how would you prepare 445 grams of solution containing 13% mass HCL from 34.1 mass % of HCL solution

    asked by SDW on February 24, 2014
  54. Math

    How many centiliters of pure acid must be added to 6 centiliters of a 50% acid solution to obtain a 70% solution?

    asked by Monica on November 24, 2010
  55. math

    How much stock solution of hydrogen peroxide 8% will you need to make 320ml of hydrogen peroxide 2% solution?

    asked by Anonymous on December 9, 2012
  56. chemistry

    Prepare 600mL of a 100mM solution of glucose in 0.9% NaCl. Also need to prepare the 0.9% NaCl solution.

    asked by margrav2 on December 5, 2010
  57. Please check my math questions.

    I only need y'all to check my responses. Thanks in advance! Is (0,3) a solution to the equation y=x+3 Yes**My choice No Is (1,-4) a solution to the equation y=-2x Yes No**My choice

    asked by Derpy Pegasus on September 30, 2015
  58. AB Calculus

    So I'm supposed to verify the solution of the differential equation. The solution is y=e^(-x). The differential equation is 3y' + 4y = e^(-x). What is the problem asking me to do here?

    asked by Hannah on February 27, 2012
  59. Math

    You have 8 liters of a 60% alcohol solution. How many liters of water should be added to make a 35% alcohol solution?.

    asked by Help Please! on December 11, 2015
  60. chemistry

    how to make 3.0 liters of a 0.98 molar HCl solution from a 10.5 molar HCl stock solution.

    asked by florence on September 18, 2013
  61. algebra

    how many liters of water should be added to a 20 liters of 40% acid solution to obtain a 30% acid solution?

    asked by elbert adonis on April 19, 2014
  62. Alg

    order your answers from smallest to largest x, then from smallest to largest y. If there is no solution, enter NO Solution 2x^2+3y^2=48 x^2-y^2=4 (x,y)= ( , ) (, ) (x,y)= ( , ) (, ) (x,y)= ( , ) (, ) (x,y)= ( , ) (, )

    asked by K on May 2, 2014
  63. Chemistry

    When 23.5 mL of 0.12 M HCl are added to 50.0 mL of a 0.15 M solution of a weak monoprotic base, the pH of the solution is 10.00. What is the Kb of the weak base?

    asked by . on March 10, 2019
  64. Chemistry

    How would I find the volume of 30% hydrogen peroxide solution from 20mL of 3% hydrogen peroxide solution?

    asked by Zach on September 28, 2012
  65. Chemistry

    how would I make 5.5 liters of a 2.5 molar HCl solution from a 10.5 molar HCl stock solution?

    asked by jake on June 12, 2011
  66. Chemistry

    A weighed amount of sodium chloride is completely dissolved in a measured volume of 4.00 M ammonia solution at ice temperature, and carbon dioxide is bubbled in. Assume that sodium bicarbonate is formed until the limiting reagent is entirely used up. The

    asked by JUNDY on February 25, 2015
  67. Chem

    Consider a solution that contains both C5H5N and C5H5NHNO3. (Kb for pyridine, C5H5N, is 4.0 x 10^-4) (a) Calculate the ratio of [C5H5N]/[C5H5NH+] if the solution has a pH of 4.50. (b) Calculate the ratio of [C5H5N]/[C5H5NH+] if the solution has a pH of

    asked by Fred on April 7, 2009
  68. urgent chem help ( dr bob plz)

    A particular household ammonia solution (d= 0.97g/mL) is 6.8% NH3 by mass. How many milliliters of this solution should be diluted with water to produce 650 mL of a solution with pH = 11.50? ============================ first i did was ph = 11.50 PH=

    asked by javeya on February 17, 2009
  69. chemistry

    what evidence supports the clarification that H2Se 03 is an acid and how do i identify the positive ions present inthe aqueous solution I am a little confused by the word "clarification" in your question. What evidence do you have? Could you measure the pH

    asked by mickey on January 30, 2007
  70. chemistry

    suppose that you have a micro pipet which delivers 100 drops per cubic centimeter, and a solution of 5.0% by volume of oil in alcohol. if you had used 10 drops of this solution, how many cubic centimeters of pure oil would be left after evaporation of the

    asked by diana on September 18, 2016
  71. chemistry

    In the following experiment, a coffee-cup calorimeter containing 100 mL of H2O is used. The initial temperature of the calorimeter is 23 degrees Celsius. If 4.00 g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution in

    asked by Katherine on October 19, 2009
  72. College Chemistry Lab

    Determine the molarity of FD&C Yellow #5 in the following solution that's prepared by mixing the dye solution with water and alcohol. None of the solutes react with one another. 6.35x10^-5M FD&C Yellow #5 = 6.50mL deionized water = 6.50mL ethyl alcohol =

    asked by L** on March 16, 2010
  73. Chemistry

    You are trying to find the heat (qrxn) in joules. C is 4.19 Change in temp is -2.2 I don't know how to find the mass if they tell me that the density of the solution is 1.02 and that the volume of water is 100 mL (Should I use the mass of the solution I

    asked by Sary on November 3, 2017
  74. chemistry

    You extract the iron from a tablet and dilute that to 350.0 ml in a volumetric flask. You transfer 0.500 ml of this solution to a 75.0 ml volumetric flask and dilute this to volume. When you measure the concentration of this solution, you find that it is

    asked by Kelcie on October 28, 2012
  75. Chemistry

    You extract the iron from a tablet and dilute that to 250.0 ml in a volumetric flask. You transfer 0.400 ml of this solution to a 25.0 ml volumetric flask and dilute this to volume. When you measure the concentration of this solution, you find that it is

    asked by Spider on April 11, 2013
  76. chemistry

    Concentrated phosphoric acid,H3PO4 was added slowly into some water to produce 5.0dm^3 of a dilute acid solution.100g of the pure phosphoric acid,H3PO4 was present in the solution.Find the concentration of the acid,in g dm^-3.

    asked by mandy on May 5, 2014
  77. chemistry

    At 29.6 degrees C, pure water has a vapor pressure of 31.1 torr. A solution is prepared by adding 86.7 g of "L" a nonvolatile nonelectrolyte to 390.0 g of water. The vapor pressure of the resulting solution is 27.6 torr. Calculate the molar mass of "L"

    asked by J on February 13, 2015
  78. Chemistry

    a 15ml sample of sulfuric acid was titrated against a solution of .0100 mol per litre of sodium hydroxide. to bring about neutralization, 25.00 ml of sodium hydroxide solution was required. calculate the concentration of the sulfuric acid

    asked by Omaaaaaaaar on January 24, 2013
  79. Chemistry

    A buffer is prepared by mixing 0.30 mole of formic acid (HCNO2) and 0.20 mole of sodium formate (NaCHO2) in enough water to make 0.50 liter of solution. Ka of formic acid is 1.7 x 10-4. Calculate the pH of the resulting buffer solution.

    asked by Sam on March 7, 2012
  80. science

    Please help. Concentrated hydrochloric acid is a 38% w/w solution of HCL in water and has a density of 1.18g/ml. How many millilitres of concentrated hydrochloric acid are needed to prepare 500ml of a 1:200 w/v HCL solution? My answer is 2.12ml. I'm not

    asked by Peter on May 9, 2012
  81. Chem2

    Copper(II) iodate precipitates from iodate solution. The formula of the precipitate is CU(IO3)2. A saturated solution of this substance was made in 0.01 M KLO3. The copper concentration was found to be 0.0013 M. Determine the [IO3-] and Ksp of the

    asked by Sammie on October 12, 2010
  82. Chemistry

    A solution of potassium hydroxide is in equilibrium with an undissolved solute at 45 degrees Celsius. What will happen to the mass of the potassium hydroxide if the temperature is raised to 50 degrees Celsius? (Given that heat of solution is

    asked by Dayton on December 14, 2012
  83. Algebra

    please check my answers. thanxs! Solve the polynomial inequality and graph the solution set on a number line. Express the solution set in interval notation. x^2 - 6x + 5 > 0 -I got (-ininity,1) u (5, infinity) x^2 - 3x - 18 < 0 -I got (-infinity,-3) u (6,

    asked by Liz on October 24, 2007
  84. chemistry

    Please help. Concentrated hydrochloric acid is a 38% w/w solution of HCL in water and has a density of 1.18g/ml. How many millilitres of concentrated hydrochloric acid are needed to prepare 500ml of a 1:200 w/v HCL solution? My answer is 2.12ml. I'm not

    asked by Peter on May 7, 2012
  85. chemsitry

    100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. calculate final molarity of h2s04 solution, if final density is 1.25g/ml. Answer 0.227M Who helps me to solve it Thank you a lot

    asked by Ferda on December 28, 2014
  86. Inequality

    please check my answers. thanxs! Solve the polynomial inequality and graph the solution set on a number line. Express the solution set in interval notation. x^2 - 6x + 5 > 0 -I got (-ininity,1) u (5, infinity) x^2 - 3x - 18 < 0 -I got (-infinity,-3) u (6,

    asked by Liz on October 23, 2007
  87. Pre-Cal

    An equation is given. (Enter your answers as a comma-separated list. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.) 2 cos 2θ − 1 = 0 a). Find all solutions of the equations answer--> θ= (π+6nπ)/6 ,

    asked by Amber on July 11, 2016
  88. Chemistry

    (Ksp= 5.0*10^-13) 1) Calculate the molar solubility of AgBr in 3.0×10^−2 M AgNO3 solution. 2) calculate the molar solubility of AgBr in 0.10 M NaBr solution. I tried solving using this the quadratic formula, but it didn't work. I started with these

    asked by Jonah on March 17, 2013
  89. chem

    An impure sample of (COOH)2 ·2 H2O that has a mass of 3.4 g was dissolved in water and titrated with standard NaOH solution. The titration required 42.7 mL of 0.156 molar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample. Answer in units

    asked by lois on April 3, 2016
  90. Chemistry

    At 21.0 °C, a solution of 23.71 g of a nonvolatile, nonpolar compound in 30.64 g of ethylbromide, C2H5Br, had a vapor pressure of 319.7 torr. The vapor pressure of pure ethyl bromide at this temperature is 400.0 torr. Assuming an ideal solution, what is

    asked by Luke on July 14, 2014
  91. chemistry

    The volume of an aqueous solution of NaCl at 25oC is expressed as a function of the amount m in 1kg of solvent in the following form; V/cm3 = 1000.94 + 16.4 (m/mol) + 2.14 (m/mol)3/2 - 0.0027 (m/mol)5/2 Find the partial molar volume of NaCl and water in 1

    asked by pritisha on August 13, 2018
  92. chemistry

    A sample of 10.00g of a solid unknown was dissolved in 25.00g of water. Assuming that pure water freezes at 0.0°C and the solution freezes at -5.58°C, what is the molal concentration of the solution? What is the molar mass of the solid? Show your

    asked by paula on January 24, 2015
  93. Chemistry

    CaCl2(s) Ca2+(aq) + 2 Cl-(aq) H = -81.5 kJ A 14.0 g sample of CaCl2 is dissolved in 130. g of water, with both substances at 25.0°C. Calculate the final temperature of the solution assuming no heat lost to the surroundings and assuming the solution has a

    asked by Joe on November 10, 2007
  94. chemistry

    When 25.0 mL of 1.0 M H2SO4 is added to 50.0 mL of 1.0 M NaOH at 25.0 °C in a calorimeter, the temperature of the aqueous solution increases to 33.9 °C. Assuming the specific heat of the solution is 4.18 J/(g·°C), that its density is 1.00 g/mL, and

    asked by nobody on March 14, 2013
  95. chemistry

    A solution is made by dissolving 46.5g of urea, (CH4N2O) a nonelectrolyte, in 316g of water. Calculate the vapour pressure of this solution at 40 oC. (ans in torr, note the vapour pressure of pure water at 40 oC is 55.3 torr.) I have been struggling with

    asked by wini on February 17, 2011
  96. Chemistry

    You have a stock 0.100 M solution of KMnO4 and a series of 100-mL volumetric flasks. What volumes of the stock solution will you have to pipet into the flasks to prepare standards of 1.00, 2.00, 5.00, and 10.0x10^-3M KMnO4 solutions? I tried using

    asked by confused on March 19, 2013
  97. intermediate algebra

    inequalities –1 ≤ x – 3 ≤ 5 –2x – 5 < –2 or x – 3 < –10 Be careful of how a negative x-term is handled in the solving process. Show all math work arriving at the solutions. •Show the solution sets written algebraically and as a union or

    asked by sean on March 15, 2017
  98. ap chem

    a solution is prepared by dissolving 4.87 g of sodium dichromate in 25.0 ml of water. (d=1.00g/mL).calculate a. the mass percent of sodium dichromate in the solution. b. the mass percent o water in the solution. c the mole fraction of sodium dichromate in

    asked by just on February 20, 2007
  99. algebra

    Mixture Problems Template – Price Problems Copy the problem from the lesson: 1. A store manager wishes to reduce the price on her fresh ground coffee by mixing two grades. If she has 50 pounds of coffee which sells for $10 per pound, how much coffee

    asked by bianca on November 17, 2010
  100. chemistry

    A certain substance has a solubility of 12 grams in 100 grams of water at 20°C. This means that _____ the substance will begin to dissolve when 12 grams are present in solution when 12 grams of the substance are stirred into a beaker with 100 g of water,

    asked by Bleaktuber on January 24, 2019