chem

posted by .

0.1802 g sample of a chlorocarbon compound was analyzed by burning in oxygen and collecting the evolved gases in a solution of sodium hydroxide. After neutralizing, the sample was treated with 39.50 mL of a 0.025 M AgNO3. This precipitated the Cl- as AgCl and left an excess of silver nitrate. This excess required 27 mL of 0.006 M KSCN in a Volhard titration. Calculate the %w/w Cl (MM = 35.45 g/mol) in the sample. [Answer in 2 decimal places]

Given:

Cl- + AgNO3 → AgCl + NO3-

AgNO3 + KSCN → AgSCN + KNO3

  • chem -

    millimols AgNO3 initially = 39.50 mL *0.025 M = ?
    mmols KSCN used to back titrate = 27.0 x 0.006 M = ?
    Subtract initial mmols - back titrated mmols = difference which is the amount AgNO3 used; i.e., it's the mmols AgCl produced.
    Convert to mols, change to grams Cl, calculate % w/w by
    %chloride = (g Cl/mass sample)*100 = ?

  • chem -

    how do you convert mmols to mols?

  • chem -

    Divide by 1000.
    mols = millimoles/1000

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. ap chemistry

    18. Answer the following question that relate to the analysis of chemical compounds. (a) A compound containing the elements C, H, N, and O is analyzed. When a 1.2359g sample is burned in excess oxygen, 2.241g of CO2(g) is formed. The …
  2. chemistry

    a sample of indium chloride is known to be contaminated with sodium chloride. The contaminated sample weighs 2.87 g. When the contaminated sample is treated with excess AgNO3(aq), 5.79 grams of AgCl(s) are obtained. What is the percentage …
  3. Chemistry

    The concentration of a certain sodium hydroxide solution was determined by using the solution to titrate a sample of potassium hydrogen phthalate (abbreviated KHP). KHP is an acid with one acidic hydrogen and a molar mass of 204.22 …
  4. Chemistry

    If 43.2 mL of 2.46 M HClO4 solution completely reacts with a 75.0 mL sample of a sodium hydroxide solution, what is the molarity of the sodium hydroxide solution?
  5. Chemistry

    A sodium hydroxide sample is contaminated with sodium chloride. A 0.240 gram sample of this impure sample is dissolved in water and titrated with 21.50 mL of 0.130 M H2C2O4. Calculate the percent sadium hydroxide in the impure sample …
  6. general chemistry

    a solution of sulfuric acid was titrated with sodium hydroxide. if you took 23.7 mL of .025 M NaOH to reach the endpoint with a 5.0 mL sample of the acid what was its concentration?
  7. chemistry

    A 0.1028 g impure sample consists of Na2CO3 was analyzed by the Volhard method. After adding 50.00 mL of 0.06208 M AgNO3, the sample was back titrated with 0.06261 M KSCN, requiring 28.36 mL to reach the end point. Report the purity …
  8. chemistry

    a) The combustion of an organic compound in the presence of excess oxygen produced a gas , which makes clear lime water turbid. What element can be identified?
  9. chemistry

    a) The combustion of an organic compound in the presence of excess oxygen produced a gas , which makes clear lime water turbid. What element can be identified?
  10. CHEMISTRY

    You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l. 2. You have a sample which consists …

More Similar Questions