Brief and simple explanation only.

tHANK YOU.
Transcribed Image Text:6. What is the purpose of adding NaAc to the centrifugate that may contain Cro (procedure 9-12-2)?
Transcribed Image Text:9-11 To the centrifugate from procedure 9-9, add dropwise 1M Ba(Ac)2 dropwise, until precipitation is complete. Centrifuge. Reserve centrifugate for procedure 9-13. Precipitate may be composed of BaSO4 and BaCrO4. 9-12 Wash precipitate with 10 drops of water and discard washings. Treat precipitate with 9-12-2 Centrifugate may contain CrO. Add 10 2- 4 5 drops of 3M HCI, stir, and centrifuge 9-12-1 Precipitate may be BaSO4. Add 10 drops of 2.5M NaAc. Yellow precipitate confirms the presence of CrO2-. drops of 3M HCI. White precipitate confirms presence of SO 3- 9-13 To 3 drops of centrifugate from procedure 9-11, add 5 drops of AGAC and acidify with 3M HNO3. No precipitation may indicate the presence of CIO3, BO3 NO₂ and NO₂. Divide centrifugate into four equal portions. 9-13-3 78. Unit 2 Qualitative Chemistry 9-13-1 1st portion Add 5 drops of conc. HNO3 and 2 drops of 0.5M AgNO3 and allow mixture to stand for 2 min. Centrifuge and discard any precipitate formed. To the centrifugate, add a few small crystals of NaNO₂ and stir. Formation of white precipitate confirms the presence of CIO3. 9-13-2 2nd portion Place the portion in a casserole. Add 5 drops of conc. H₂SO4 and evaporate to almost dryness. Let casserole cool. Add 10 drops of methyl alcohol (CH3OH) and ignite the whole mixture. Green bordered flame confirms the presence of BO3³. 10% COMEN ÓW,noluloz wolley to bibligipaiq entuminos 100X192910 3rd portion To the centrifugate in a test tube, add an equal volume of urea in HCI solution. Vigorous evolution of a gas indicates the presence of NO₂. bbA OH MC 10 no wo loz tehly B0002914 bro wst 10 200 beroobri 200b Of bbA hol JOO*** bno yol nf 9-13-4 4th portion Make two tests for NO3. a. To 2 drops of the centrifugate in a spot plate depression, add 2 drops of conc. H₂SO4 and 1 drop of a-naphthylamine. Allow it to stand for 3 min. Appearance of a purple ring around the drop of reagent indicates the presence of NO3. ho b. Place a small crystal of ferrous sulfate stics in a depression on armiin of a spot plate. to pomez Add 2 drops of the centrifugate and 2 drops of conc. H₂SO4. Formation of a brown ring around the crystal indicates the presence of NO₂. 1. 2. 3. 4. A Gilre Holtz C Wisn Zum

Question

Brief and simple explanation only.  tHANK YOU. 6. What is the purpose of adding NaAc to the centrifugate that may contain Cro(procedure 9-12-2)? 9-11 To the centrifugate from procedure 9-9, add dropwise 1M Ba(Ac)2 dropwise, untilprecipitation is complete. Centrifuge. Reserve centrifugate for procedure 9-13.Precipitate may be composed of BaSO4 and BaCrO4.9-12 Wash precipitate with 10 drops of water and discard washings. Treat precipitate with9-12-2 Centrifugate may contain CrO. Add 102-45 drops of 3M HCI, stir, and centrifuge9-12-1 Precipitate may be BaSO4. Add 10drops of 2.5M NaAc. Yellow precipitateconfirms the presence of CrO2-.drops of 3M HCI. White precipitateconfirms presence of SO3-9-13 To 3 drops of centrifugate from procedure 9-11, add 5 drops of AGAC and acidify with3M HNO3. No precipitation may indicate the presence of CIO3, BO3 NO₂ and NO₂.Divide centrifugate into four equal portions.9-13-378. Unit 2 Qualitative Chemistry9-13-11st portionAdd 5 drops ofconc. HNO3 and2 drops of 0.5MAgNO3 and allowmixture to stand for2 min. Centrifugeand discard anyprecipitate formed.To the centrifugate,add a few smallcrystals of NaNO₂and stir. Formationof white precipitateconfirms thepresence of CIO3.9-13-22nd portionPlace the portion ina casserole. Add 5drops of conc. H₂SO4and evaporateto almost dryness.Let casserole cool.Add 10 drops ofmethyl alcohol(CH3OH) and ignitethe whole mixture.Green borderedflame confirms thepresence of BO3³.10%COMENÓW,nolulozwolley tobibligipaiqentuminos100X1929103rd portionTo the centrifugatein a test tube, addan equal volume ofurea in HCI solution.Vigorous evolution ofa gas indicates thepresence of NO₂.bbAOH MC 10nowoloz tehlyB0002914browst 10 200beroobri200b Of bbAholJOO***bnoyolnf9-13-44th portionMake two tests for NO3.a. To 2 drops ofthe centrifugatein a spot platedepression, add2 drops of conc.H₂SO4 and 1 drop ofa-naphthylamine.Allow it to stand for3 min. Appearanceof a purple ringaround the drop ofreagent indicatesthe presence ofNO3.ho b. Place a small crystalof ferrous sulfatestics in a depressionon armiin of a spot plate.to pomez Add 2 drops of thecentrifugate and2 drops of conc.H₂SO4. Formation ofa brown ring aroundthe crystal indicatesthe presence ofNO₂.1.2.3.4.AGilreHoltzCWisnZum

Accepted Answer

NaAc is sodium acetate. Its formula is CH3COONa