Chapter 35, Problem 2ASA

Which of the following would lead to a negative percentage error in the determination of Ksp of Ca(OH)2?  a. Unsaturated Ca(OH)2 solution was used in the titration. b. The volume of saturated CaCl2 used in the titration was in excess. c. The volume of HCl used was beyond the equivalence point of the reaction. d. A more concentrated HCl solution was used in the titration of Ca(OH)2.

P 20 11 pH W . 1 V S . Titration Curve for aqueous Hypobromous solution Volume of Tant Added (n) The chemist making the pH curve above added bromothymol blue to the sample of aqueous hypobromous solution before starting the test. What colour change occured during the test? Select one: O The sample remained blue. O The sample remained yellow. O The sample went from blue to yellow. O The sample went from yellow to blue.

Xanthoproteic Test To 2 mL of sample add 1 mL concentrated HNO3. Observe whether a heavy white precipitate is formed. Heat carefully and observe whether the precipitate turns yellow and finally dissolves. Record the color of the precipitate and/or the solution. Cool and make alkaline with 10% NaOH. Record the color. Question 1. What do you think was the white precipitate formed after the addition of nitric acid and why did it turn to yellow after heating?  Question 2. Why did the mixture change in color after addition of 10% NaOH?  Question 3. Will it give positive test to all the proteins?

1. What process is responsible for the increase in the total negative charge as soil pH increases? a.Protonation b. Dehydration reaction c. H+ bond formation d. Deprotonation   2. What ionic form of nutrient would most likely be easily leached/washed out from the soil? a. Cation b. Conjugate ion c. Anion d. Spectator ion   3. When a soil with cation-Ca complexed is poured with distilled water, what would you expect if the leachate will be reacted with ammonium oxalate? a.The leachate will be negative for calcium b. The leachate will manifest a false negative c. The leachate will be positive for Calcium d. The leachate will manifest a false positive

17. This type of analysis implies that the constituent determined was present in very, very low concentration. a. Macro analysis b. Semi-macro analysis c. Micro analysis 18. Which of the following does not happen during digestion? The crystals dissolve and re-precipitate under equilibrium conditions. b. Weakly bound water are lost from the precipitates. c. Filterability improves d. None of the choices

4. Out of the following metallic cations in solution, which would precipitate last when Na2S(s) is added to the solution? a. Cd²+ b. Mn2+ c. Hg2+ d. Pb²+ e. Fe2+

Give the formula of the compound which will give a precipitate with BaCl2 but NOT with (NH4) 2CO3? a. AgNO3 b. Zn (NO3) 2 c. KCl   d. Na2 SO4

48. A saturated solution of which compound has the highest [Ca2+] A. CaF (Ksp = 4.1x10-11)  B. CaCO3 (Ksp = 8.7 x 10-9) C. Ca(OH)2 (Ksp = 8.0 x 10-6) D. CaSO4  (Ksp = 2.4 x 10-5) E. More information is needed.

1. How quantity Qsp and Ksp can be used in predicting precipitate formation? 2. How precipitation titrations work? 3. How will you differentiate Mohr method, Volhard method and Fajans method?