tomi

Newest questions and responses by tomi
  1. Chemistry

    nitrogen gas is at 2.00. c, 2.00 atm pressure and occupies a volume of 10.01. Assume nitrogen is an ideal gas, how many moles of the gas are present?

    asked on November 4, 2012
  2. Consumer math !!!! please check

    Determine the total in Dexter's account after the second month using the information below. Dexter Banler's account Principal: $1,604 Rate: 10% compound Length of period: month >$3208.00 $1764.40 $1630.85 3. Ray Sugar's account Principal: $1,700 Rate: 9.5%

    asked on May 24, 2012
  3. physics

    5. If a quantity increases as a second quantity decreases and decreases as the second quantity increases, the two quantities are said to be: A_Directly proportional B_Inversely proportional C_Completely unrelated D_Blue and red

    asked on May 22, 2012
  4. calculus

    from the first principles,find the deriviative of 3/x with espect to x

    asked on February 4, 2012
  5. chem

    1.Pippete 20ml of 0.1M acetic acid and 20ml of 0.1M NaOH into a 100ml beaker (Remember that the final volume of this solution is the sum of the volumes of the acetic acid and NaOH solutions that have been mixed) 2. Pippete 20ml of 0.1 acetic acid into

    asked on April 26, 2009
  6. biology

    If you were to use an aquatic plant for your starting material, what would you expected to see in terms of pigments and absorption spectra, in comparison to results from a spinach? Explain.

    asked on April 26, 2009
  7. chem

    A sample of 7.80L of NH3 (ammonia) gas at 22 degrees and 735mmHg is bubbled into a 0.350L solution of 0.400M HCL(hydrochloric acid). The Kb value for NH3 is 1.8x10-5 Assuming all the NH3 dissolves and that the volume of the solution remains at 0.350L ,

    asked on April 23, 2009
  8. chem

    A 75.0mL sample of 1.56×10−2M Na2SO4(aq) is added to 75.0mL of 1.22×10−2M of Ca(NO3)2(aq). What percentage of the Ca+ remains unprecipitated?

    asked on April 23, 2009
  9. chem

    You are asked to bring the pH of 0.500L of 0.450M NH4Cl to 7.00. a) Which of the following solutions would you use: 10.0M HCl or 10.0M NH3? I figured that one would use the 10.0M NH3 b)How many drops (1 drop 0.05mL) of this solution would you use?

    asked on April 23, 2009
  10. chem

    A sample of 7.80L of NH3 (ammonia) gas at 22 degrees and 735mmHg is bubbled into a 0.350L solution of 0.400M HCL(hydrochloric acid). The Kb value for NH3 is 1.8x10-5 Assuming all the NH3 dissolves and that the volume of the solution remains at 0.350L ,

    asked on April 22, 2009
  11. chem

    A 75.0mL sample of 1.56×10−2M Na2SO4(aq) is added to 75.0mL of 1.22×10−2M of Ca(NO3)2(aq). What percentage of the Ca+ remains unprecipitated?

    asked on April 22, 2009
  12. chem

    You are asked to bring the pH of 0.500L of 0.450M NH4Cl to 7.00. a) Which of the following solutions would you use: 10.0M HCl or 10.0M NH3? I figured that one would use the 10.0M NH3 b)How many drops (1 drop 0.05mL) of this solution would you use?

    asked on April 22, 2009
  13. chem

    A sample of 7.80L of NH3(ammonia) gas at 22 degrees Celsius and 735torr is bubbled into a 0.350L solution of 0.400M HCl (hydrochloric acid). The Kb value for NH3 is 1.8x10-5. Assuming all the NH3 dissolves and that the volume of the solution remains at

    asked on April 16, 2009
  14. chem

    Calculate [H3O] in the following solutions. 5.15x10-2M HCl and 7.62x10-2M NaC2H3O2 Responses HCl + NaC2H3O2. It appears there is an excess of H^+ which will react with NaC2H3O2 to form HC2H3O2. That gives you a buffer of C2H3O2 and HC2H3O2 and you use the

    asked on April 16, 2009
  15. chemistry

    Calculate [H3O] in the following solutions. a)4.0×10−2M HCl and 8.0×10−2M HOCl b)0.105M NaNO2 and 5.00×10−2M HNO2 c)5.15x10-2M HCl and 7.62x10-2M NaC2H3O2

    asked on April 15, 2009
  16. chem

    The following equation describes the oxidation of an acidified solution of sodium oxalate (Na2C2O4) by potassium permanganate(KMnO4) 5C2O4 + 2MnO4 + 16H2SO4 --> 10CO2 + 2Mn + 16HSO4 + 8H20 What volume of 0.127M sodium oxalate in sulphuric acid will react

    asked on April 7, 2009
  17. chem

    Lead metal is added to 0.140M Cr^+3(aq). Pb(s)+ 2Cr^3+(aq)---> Pb^2+(aq) + 2Cr^2+(aq) a)What is [Pb^2+] when equilibrium is established in the reaction? b)What is [Cr^2+] when equilibrium is established in the reaction? c)What is [Cr^3+] when equilibrium

    asked on April 3, 2009
  18. chem

    Lead metal is added to 0.140M Cr^+3(aq). Pb(s)+ 2Cr^3+(aq)---> Pb^2+(aq) + 2Cr^2+(aq) a)What is [Pb^2+] when equilibrium is established in the reaction? b)What is [Cr^2+] when equilibrium is established in the reaction? c)What is [Cr^3+] when equilibrium

    asked on April 3, 2009
  19. chem

    The following reaction is used in some self-contained breathing devices as a source of O2. 4KO2(s) + 2C02(g)---> 2K2CO3(s) + 3O2(g) Suppose that a sample of CO2(g) is added to an evacuated flask containing KO2(s) and equilibrium is established. The

    asked on April 2, 2009
  20. chem

    The pH of saturated Sr(OH)2 is found to be 13.12. A 15.0ml sample of saturated Sr(OH)2 is diluted to 250.0ml in a volumetric flask. A 15.0ml sample of the diluted Sr(OH)2 is transferred to a beaker, and some water is added. The resulting solution requires

    asked on April 2, 2009
  21. chemistry......plz help

    A solution is prepared by dissolving 10.00g of a monobasic salt in a total volume of 1.00litres. Th pH of this solution was measured at 13.07 and a conductivity experiment determined that this salt was completely ionized in solution. What is the molecular

    asked on March 24, 2009
  22. chemistry

    A solution is prepared by dissolving 10.00g of a monobasic salt in a total volume of 1.00litres. Th pH of this solution was measured at 13.07 and a conductivity experiment determined that this salt was completely ionized in solution. What is the molecular

    asked on March 23, 2009
  23. chemistry

    A solution is prepared by dissolving 10.00g of a monobasic salt in a total volume of 1.00litres. Th pH of this solution was measured at 13.07 and a conductivity experiment determined that this salt was completely ionized in solution. What is the molecular

    asked on March 23, 2009
  24. chemistry

    The enzyme Y catalyzes the elementary reaction AB-->A + B An enzyme concentration of 1.0M Y can convert a maximum of 0.5M AB to the products A and B per second. What will happen when each of the following is added to a solution that contains 1.0M Y and

    asked on March 23, 2009
  25. chem

    A student placed 12.5 of glucose (C6H12O6) in a 100ml volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the calibration mark on the neck of the flask was reached. The flask was then shaken

    asked on March 12, 2009
  26. chemistry

    A student placed 12.5 of glucose () in a 100.- volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the calibration mark on the neck of the flask was reached. The flask was then shaken until

    asked on March 12, 2009
  27. Computer science

    If the last value of Period is less than the number of periods specified in the Parameters worksheet, increment the Period value by 1, otherwise blank the cell(i.e. ""). What does this mean in spreadsheer syntax for excel using the IF function

    asked on January 26, 2009
  28. english

    "context affects content" what does this mean

    asked on January 9, 2009
  29. chem

    i have to catogerize the list based on which is ionic, polar covalent, and nonpolar covalent 1.SI 2.HBr 3.HP 4.SO 5.BeF 6.BeCl 7.ScO

    asked on November 19, 2008
  30. chem

    What is the boiling point of water at an elevation of 1.55×10^4 ft ? The atmospheric pressure at sea level is 760mmHg . This pressure decreases by 19.8mmHg for every 1000-ft increase in elevation. The boiling point of water decreases 0.05 degrees celsius

    asked on November 19, 2008
  31. chem

    The normal boiling point of water is 100.00 degrees celsius and the enthalpy of vaporization at this temperature is 40.657kj/mol. What would be the boiling point of water if it were based on a pressure of 1 bar instead of the standard atm?

    asked on November 19, 2008
  32. chem

    What is the longest wavelength of light that will provide photons of sufficient energy to break the pi bond and cause the isomerization? Energy required to break pi bond is 4.42*10^-19. wavelenght=c/f but how do i figure out what f is?

    asked on November 13, 2008
  33. chem

    What is the longest wavelength of light that will provide photons of sufficient energy to break the pi bond and cause the isomerization? Energy required to break pi bond is 4.42*10^-19. wavelenght=c/f but how do i figure out what f is?

    asked on November 13, 2008
  34. chem

    Use bond energies to estimate the enthalpy change for the following reaction C2H2 + H2-> C2H4 i figured the bonds broken are: 1 C triple bond C 1(812kj/mol) 2 C-H 2(414kj/mol) 1 H-H 1(435kj/mol) Bonds formed 1 C=C 1(590kj/mol) 4 C-H 4(435kj/mol) Is this

    asked on November 12, 2008
  35. chem

    The average bond enthalpy for a C=C double bond is 614kj/mol and that of a C-C single bond is 348kj/mol . Estimate the energy needed to break the pi bond in 2-butene. CH3 CH3 CH3 H \ / \ / C=C ------> C=C / \ / \ H H H CH3 Cis-2-butene Trans-2-butene

    asked on November 12, 2008
  36. Chem

    Draw the electron-dot structure for CHClO.

    asked on November 12, 2008
  37. chem

    a compound containing only boron, nitrogen and hydrogen was found to be 40.3% B, 52.2%N, and 7.5% H by mass. If 3.301g of this compound is dissolved in 50.00g of benzene, the solution produced freezes at 1.30 degrees celsius. If Kf(freezing point

    asked on November 8, 2008
  38. chem

    a compound containing only boron, nitrogen and hydrogen was found to be 40.3% B, 52.2%N, and 7.5% H by mass. If 3.301g of this compound is dissolved in 50.00g of benzene, the solution produced freezes at 1.30 degrees celsius. If Kf(freezing point

    asked on November 7, 2008
  39. chemistry

    a mixture is prepared using equal masses of two volatile liquid benzene, C6H6 and ethanol C2H5OH. what is the mole fraction of benzene in this mixture?

    asked on October 27, 2008
  40. chem

    What electron transition in a hydrogen atom, starting from the orbit 10, will produce infrared light of wavelength 3040 ?

    asked on October 26, 2008
  41. chem

    How much energy, in joules, must be absorbed to convert to Na all the atoms present in 1.00mg of gaseous Na? The first ionization energy of Na is 495.8kj/mol .

    asked on October 26, 2008
  42. chemistry

    Zinc dissolves in acid according to the balanced equation. Zn(s)+ 2H(aq)-> Zn(aq) + H2(g) a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy

    asked on October 22, 2008
  43. chem

    Zinc dissolves in acid according to the balanced equation. Zn(s)+ 2H(aq)-> Zn(aq) + H2(g) a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy

    asked on October 20, 2008
  44. chem

    Zinc dissolves in acid according to the balanced equation. Zn(s)+ 2H(aq)-> Zn(aq) + H2(g) a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy

    asked on October 18, 2008
  45. chem

    A calorimeter contains 16.0ml of water at 15.0degrees celsius. When 1.60g of X(a substance with a molar mass of 46.0g/mol) is added, it dissolves via the reaction X(s)+H20(l)->X(aq) and the temperature of the solution increases to 25.0degrees celsius.

    asked on October 8, 2008
  46. chem

    The complete combustion of butane, (g) is represented by the equation C4H10+13/2O2->4CO2+5H20 STANDARD ENTHALPY IS -2877KJ/MOL How much heat, in kilojoules, is evolved in the complete combustion of 12.8L C4H10 at 23.8degrees celsius and 744mmhg ?

    asked on October 8, 2008
  47. chem

    The complete combustion of butane, (g) is represented by the equation C4H10+ 13/2O2->4CO2+5H2O standard enthalpy is -2877kj How much heat, in kilojoules, is evolved in the complete combustion of 12.8ml at 23.8degrees celsius and 744mmhg ?

    asked on October 8, 2008
  48. chem

    Calculate the standard enthalpy change for the reaction 2A+B->2C+D Use the following data: Substance A=-257kj/mol B=-413kj/mol C=189kj/mol D=-475kj/mol For the reaction given , how much heat is absorbed when 3.00mol of A react?

    asked on October 8, 2008
  49. chem

    The combustion of hydrogen–oxygen mixtures is used to produce very high temperatures (approximately 2500 °C) needed for certain types of welding operations. Consider the reaction to be H2(g) + 1/2O2(g) --> H20(l) Standard enthalpy is -241.8kj What is

    asked on October 4, 2008
  50. chem

    Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles)of He(g) is present in a helium-oxygen mixture having a density of 0.538g/L at 25celsius and 721mmHg ?

    asked on September 27, 2008
  51. chemistry

    Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles)of He(g) is present in a helium-oxygen mixture having a density of 0.538g/L at 25celsius and 721mmHg ?

    asked on September 27, 2008
  52. chemistry

    A 2.34L container of H2(g)at 752mmHg and 24 degrees is connected to a 3.17L container of He(g) at 717mmHg and 24 degrees. After mixing, what is the total gas pressure, in millimeters of mercury, with the temperature remaining at 24 degrees?

    asked on September 27, 2008
  53. chemistry

    A gaseous mixture of O2 and N2 contains 32.8% nitrogen by mass How do i figure out wat the mass is?

    asked on September 20, 2008
  54. chemistry

    Determine the number of moles of a) N atoms in a sample of C7H5(NO2)3 that has the same number of O atoms as 12.6g C6H12O6 Someone posted a way to answer this question but i still don't understand

    asked on September 20, 2008
  55. chemistry

    Determine the number of moles of N atoms in a sample of C7H5(NO2)3 that has the same number of O atoms as 12.6g C6H12O6

    asked on September 20, 2008
  56. chemistry

    To determine the approximate mass of a small spherical shot of copper, the following experiment is performed. When 140 pieces of the shot are counted out and added to 8.6ml of water in a graduated cylinder, the total volume becomes 8.8ml . The density of

    asked on September 19, 2008
  57. chemistry

    Determine the number of moles of a) N atoms in 42.5g of Mg(NO3)2 b) N atoms in a sample of C7H5(NO2)3 that has the same number of O atoms as 12.6g C6H12O6

    asked on September 19, 2008
  58. algebra II, Functions, Ratios, Proportions, and Lo

    Please help me with this questions, i tried doing it by myself but they are too hard. so pleasssssssssssssssssssssssssssssssssseeee help me. 1. Shown here is the graph of which of the following equations? A. y = –x – 3 C. y = x – 3 B. y = 3 – x D.

    asked on June 22, 2007
  59. Algebra II --- Variation, Progression, and theorem

    1. If y varies inversely as x, and y = 12 when x = 6, what is K, the variation constant? A. 1⁄3 C. 72 B. 2 D. 144 2. Use the remainder theorem and the factor theorem to determine whether (y – 3) is a factor of (y4 + 2y2 – 4). A. The remainder is 0

    asked on June 22, 2007
  1. designer

    For which figure type are the line of this gown most flattering?.A tall.B. short or plump.C.Thin. D. Average

    posted on March 14, 2012
  2. chem

    nvm i figured it out

    posted on November 19, 2008
  3. Chem

    thx

    posted on November 12, 2008
  4. chem

    NVM FIGURED IT OUT

    posted on November 12, 2008
  5. chemistry

    wat do u mean by change density to stp

    posted on September 27, 2008
  6. chemistry

    still confused

    posted on September 20, 2008
  7. chemistry

    i don't get what u mean

    posted on September 19, 2008