posted by .

you extract 10 g of benzoic acid from an ether solution with aqueous NaHCO3

what is the min amount of concentrated HCl (37% by w/v%) that would be needed to convert the sodium benzoat back to free energy? (answer: 8.2 mL)
I know that the 37% is basically 37g/ 100ml but how would that help me?

How many extractions do you need in order to extract at least 95% of the benzoic acid with 15mL of methylene chloride (solvent 2) that are intially presented in 45mL of HCl (solvent 1)? You may assume that the partition coefficient to be 3.5 for the benzoic acid.(answer is 4)
I did something wrong!
10=9.5(45ml/[3.5*15 + 45])^n
solving for n and I don't get 4

Thanks for the help!

  • chemistry -

    I have
    fn = [1+ Kd*(Vo/Va)]-n.
    where fn = fraction remaining in the water layer. For 95% extraction, that would be 5/100 = 0.05 remaining.
    0.05 = 1/[1+3.5(15/45)]n
    I solve for n and I get 3.87 which would be 4 extractions.

  • chemistry -

    That character that didn't print clearly at the end of the formula is -n for the first one, and n for the second one.
    0.05 = 1/[1+3.5(15/45)]^n
    0.05 = 1/(2.1667)^n
    (2.1667)^n = 1/0.05

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. organic chemistry

    1)Why benzoic acid is soluble in NaOH? 2)Why HCl is insoluble in titration of benzoic acid and NaOH?
  2. chem

    which of the following could be used to dissolve a carboxylic acid into the aqueous phase?
  3. Org. Chem.

    what is the precipitate formed when HCl is added?
  4. Organic Chemistry

    I am suppose to calculate the theoretical amount (volume) of 3M sodium hydroxide needed to convert 1.5 g of benzoic acid to its salt. Also calculate the volume of 12M HCl needed to convert the sodium benzoate back to benzoic acid. …
  5. Organic Chemistry

    separation and purification scheme how would i begin this?
  6. Organic Chemistry - Extraction

    You have 100 mL of a solution of benzoic acid in water; the amount of benzoic acid in the solution is estimated to be about 0.30 g. The distribution coefficient of benzoic acid in diethyl ether and water is approximately 10. Calculate …
  7. Organic Chemistry

    I realize this is a general chemistry stoichiometry question, however I can not fully grasp it. I am supposed to calculate the theoretical amount (volume) of 3M sodium hydroxide (NaOH) needed to convert 1.5g of benzoic acid to its …
  8. OChem

    A mixture of fluorene and benzoic acid is dissolved in diethyl ether and mixed thoroughly with an aqueous solution of NaOH. After the layers separate, what will each of the layers contain?
  9. 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?
  10. Chemistry

    An etheral solution contains benzoic acid, 9-fluorenone, abd ethyl 4-aminobenzoate. Why would benzoic acid and 9-fluorenone not be extracted from this etheral solution by aqueous HCl ?

More Similar Questions