Identification Of Selected Anions Lab Answers

Question: Qualitative analysis

Answer: The examination of a sample of inorganic material to identify the ions that are present

Question: In some cases a tentative identification of an anion can be made from the silver nitrate test

Answer: ...

Question: What is the identification of the silver nitrate test based on?

Answer: Color of the precipitate and on whether or not the precipitate is soluble in nitric acid *usually more tests are needed to identify bc two or more anions may give similar results

Question: What can the silver nitrate test prove the presence of?

Answer: A halide ion (CL-, Br-, I-) bc the silver precipitates of the other 3 anions dissolve in nitric acid

Question: Organic solvent test

Answer: -add chlorine water (cl2) to halide salts (CL-, BR-, I-) to:--oxidize bromide ion to free bromine (br2) and iodine ion to free (i2) -can extract the halogen by adding an immiscible organic solvent (decade) and shaking. ---cl2= pale yellow , br2=yellow/orange to reddish brown, i2 = violet/ pink -pale yellow doesn't mean that cl2 was present bc it was added

Question: Formula (un-ionized) equation

Answer: NaCl (aq) + AgNO3(aq) ---> AgCl (s) +NaNO3 (aq) -shows the formulas of the substances in the equation as they were normally written

Question: Total ionic equation

Answer: Na+(aq) + Cl-(aq) + Aq+(aq) + NO3-(aq)---> AgCl(s) + Na+(aq) + NO3-(aq) -shows the substances as they occur in a solution-strong electrolytes, precipitates, and gases are written in their un-ionized or molecular form

Question: net ionic equation

Answer: Cl-(aq) + Ag+(aq) --->AgCl(s)-includes only those substances or ions in equation 2 (total ionic equation) that have undergone a chemical change -therefore Na+ and NO3- havent changed and dont appear in the net ionic equation

Question: what substances will you be putting in the test tubes

Answer: NaCl, NaBr, NaI, Na2SO4, Na3PO4, Na2CO3 and two unknowns (2mL)

Question: -dispose of solutions containing decane in the container marked...-dispose of solutions containing silver, barium in...

Answer: -"waste organic solvents"-"heavy metals waste" container

Question: writings -for precipitate, yes and no-dissolving precipitate, yes no-decane solubility test

Answer: -= "ppt formed" and write color, no= "no ppt"-yes= "ppt dissolved", no= "ppt did not dissolve"-indicate the color of the decane layer