ANAL 367: The Chemistry and Qualitative Analysis of Anions Post-Laboratory Quest

Question

ANAL 367: The Chemistry and Qualitative Analysis of Anions Post-Laboratory Questions (Use the spaces provided for the answers and additional paper if necessary is known to contain Cr, NO,-. NO- 4. A solution and SO Ions. Which of these lons can be adding 3M H2SO4 and heating, repeating this process is then analyzed for NO ion by adding FeSO, solu- tion and more H2sO4, heating the test tube and its contents. The NO3 ion reaction is positive. In this until no further reaction ocours. This solution identified? Describe the reactions used and results. case, is it accurate to state that NO3 ion was present in the original solution? Briefly explain. Write appro- priate equations to support your answer 2. A solution contains a mixture of CI and Br ions. Can both be positively identified? Briefly explain. Write appropriate equations to support your answer 5. Why wouldn't HCI be a good acid to use to deter- mine the solubility of a silver precipitate in solution? 3. The solubility product constants of AgCl, AgBr, and Ag, are, respectively, 1.7× 10-10 4.1 × 10-13 and 1.5 × 10-16 The Kip expression for each silver halide, AgX, is: Ksp = [Ag+][X-] When the ion product, [Ag 1X], exceeds the Kp AgX(s) will precipitate until the ion product once again equals Ksp If the Ag ion concentration in the mixture is 0.067M (diluted from 0.1M), calculate the detec- tion limit of this reaction for each halide, the value be- low which there will be no observed reaction.

Explanation / Answer

1) NO2- (nitrite ion ) react with conc.H2SO4 on to form gases NO,NO2 that escapes.

2NO2- + H2SO4 ----> Na2SO4 +NO+NO2 +H2O

Heating of the solution bubbles off the gases ,so that no NO2- remains in the solution.

NO3- +H2SO4 --->HNO3 + HSO4- (no gases formed)

So,it can be inferred that nitrate was present in the original solution ,so it gave positive brown ring test

2HNO3 +3H2SO4 +6FeSO4----->3Fe2(SO4)3+2NO+4H2O

[Fe(H2O)6]SO4 +NO ---->[Fe(H2O)5 (NO)]SO4 (brown ring )+H2O

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.