10 8 Phosphate test Take 10 drops of the original test solution from Step 1 and

10 8 phosphate test take 10 drops of the original

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8. Phosphate test: Take 10 drops of the original test solution (from Step 1) and add five drops of 6 M HNO 3 and five drops of 0.4 M (NH 4 ) 2 MoO 4 . Formation of a yellow precipitate confirms the presence of phosphate. All the other anions form a white precipitate. 9. Nitrate test: Add five drops of 1 M FeSO 4 solution to 10 drops of the original test solution (from Step 1) and mix thoroughly. Add 2-3 drops of 3 M H 2 SO 4 to this solution until it is acidic. Incline the test tube at a 45° angle and gently add 1 mL of concentrated H 2 SO 4 using a dropper along the sides of the test tube. Make sure that the contents of the test tube do not mix. Allow the test tube to stand for a few minutes and look for the appearance of a brown ring at the interface of the sulfuric acid layer (the bottom) and the test solution layer. Formation of the brown ring confirms the presence of nitrate ions in the original solution. 10. Oxalate test: The presence of oxalate in the unknown is determined by exclusion. If the unknown tests negative to all the above confirmatory tests, then based on the process of elimination, the unknown must be oxalate. 11
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Data Table P ART 1: A NALYSIS OF K NOWN S AMPLES Step Experiment Observation 1 Add 6 M nitric acid to a pinch of the solid carbonate salt 3 Carbonate + 0.1 M BaCl 2 6 Chloride + HNO 3 + 0.1 M AgNO 3 6 Bromide + HNO 3 + 0.1 M AgNO 3 6 Iodide + HNO 3 + 0.1 M AgNO 3 7 Chloride test 8a Bromide test 8b Iodide test 10 Sulfate + 6 M HCl followed by two drops of 0.1 M BaCl 2 12 Phosphate + five drops of 6 M HNO 3 and five drops of 0.4 M (NH 4 ) 2 MoO 4 14 Nitrate + 1 M FeSO 4 + 3 M H 2 SO 4 + concentrated H 2 SO 4 12
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P ART 2: A NALYSIS OF U NKNOWN S AMPLE Observations Step Experiment UNKNOWN 1 UNKNOWN 2 UNKNOWN 3 1 Unknown + 6 M nitric acid 3 Carbonate test 5 Halide test 6 Chloride test 7a Bromide test 7b Iodide test 8 Sulfate test 9 Phosphate test 10 Nitrate test 13
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ResultsList the relevant observations and the identity of the unknown below:UnknownNumberRelevant ObservationsIdentifyNameFormula1214 3
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