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. Calculate the initial concentrations of acetic acid, HC 2 H 3 O 2 , and acetat

ID: 1018233 • Letter: #

Question

. Calculate the initial concentrations of acetic acid, HC2H3O2, and acetate ion, C2H3O2– , in the buffer (see step #2 of the procedure).

Procedure Obtain three clean 250-mL Erlenmeyer flasks. Label one 'Buffer'. Label the second flask '0.100 M HCI. Label the third flask '0.100 M NaOH 2. To prepare 200.0 mL of buffer solution, add 20.0 mL of 1.00 M acetic acid solution to a 100-mL graduated cylinder and add enough distilled water to bring the volume to the 100.0 mL mark. Add to the 'Buffer flask. Add 20.0 mL of 1.00 M sodium acetate solution to the 100-mL graduated cylinder, add enough distilled water to bring the volume to the 100.0 mL mark. Add to the 'Buffer flask. Mix by swirling.

Explanation / Answer

CH3COOH

Intial                                                           final

M1 = 1M                                                   M2

V1   = 20ml                                                V2 = 100ml

   M1V1   = M2V2

    M2   = M1V1/V2

           = 1*20/100 = 0.2M

CH3COOH initial concentration is 1M final concentration is 0.2M

CH3COONa

Intial                                                                       Final

M1 = 1M                                                              M2 =

V1 = 20ml                                                             V2 = 100ml

       M1V1    = M2V2

           M2 = M1V1/V2

                 = 1*20/100 = 0.2M

intial concentration of CH3COONa is 1M final concentration is 0.2M