Use the titration results to calculate the moles of H_2 SO_4, that were used to

Question

Use the titration results to calculate the moles of H_2 SO_4, that were used to reach the equivalence point in each trial. Use your titration results to calculate the molar concentration (molarity) of the Ba (OH)_2 solution using the molar amount ofH2Soe used in each trial. Convert the mass of the barium sulfate precipitate, formed in each trial, to moles. Use the moles of BaSO_4 from 3 above to calculate the molarity of the Ba (OH)_2 solution. Compare the results of your calculations from 2 and 4 above with the actual molarity of the Ba (OH)_2 solution. Which method of analysis, equivalence point or gravimetric determination, was more accurate in your experiment? Why?

Explanation / Answer

Reaction taking place is:

Ba(OH)2 + H2SO4 ---> BaSO4 + 2H2O

(1)

Moles of H2SO4 used = Volume*Molarity = 0.00838*0.1 = 0.000838 moles

(2)

According to reaction stoichiometry, same number of moles of Barium hydroxide must be present.

So, molarity of Ba(OH)2 = moles/Volume = 0.000838/0.01 = 0.0838 M

(3)

Moles of BaSO4 formed in the experiment = Mass/MW = 0.61/233.38 = 0.00261 moles

(4)

According to reaction stoichiometry,

Moles of Barium hydroxide must be present = Moles of BaSO4 formed

So, molarity of Ba(OH)2 = moles/Volume = 0.000261/0.01 = 0.0261M

(5)

The results from (2) qnd (4) show that the conc. in (4) is much less than the conc in (2). So this method is not very accurate.

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---