Qualitative Analysis Chem 230 Exam 2 KSU Questions With Complete Solutions

The solution is clear and colorless correct answer: Fe 3+, Cr 3+, and Ni 2+ is absent Step B. The solution was made basic and barium hydroxide was added. A white precipitate formed. correct answer: SO4 2- is present Step C. Silver nitrate was added the precipitate dissolves. correct answer: Cl- is present Step C. A brown ring test was performed and the brown ring formed. correct answer: NO3- is present A flame test on the unknown showed a reddish color. correct answer: Ca 2+ is present Step E. Sodium hydroxide was added to the unknown and a damp piece of red litmus paper was placed on a watch glass above the solution. The litmus paper turns blue. correct answer: NH4+ is present Na2S was added, black precipitate formed. correct answer: Pb 2+ is present Ammonium hydroxide and ammonium chloride were added to a buffered solution. No precipitate was seen. correct answer: Fe 3+ and Cr 3+ are absent Step J. White precipitate forms and turns blue when heated. correct answer: Zn 2+ is present Step L. The decanted solution was made basic with ammonia. Adding dimethlglyoxime caused no visible change. correct answer: Ni 2+ is absent A flame test shows lavender correct answer: K + is present The precipitate was dissolved in HCl and K2(Fe(CN)2) was added producing a deep blue color. correct answer: Fe 3+ is present Hydrochloric acid was added to a portion of the unknown. The test tube was chilled in ice water and centrifuged. Even when scratching the stirring rod no precipitate formed. correct answer: Pb 2+ is not present. Brownish Yellow correct answer: Fe Grayish Blue correct answer: Cr Pale Green correct answer: Ni Pb with Cl or SO4 correct answer: incompattible SO4 and Ca correct answer: incompattible