Unknown 2 Scheme - *SCHEME FOR UKNOWN 2 U Unknown Scheme 2...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
**SCHEME FOR UKNOWN 2:** Unknown Scheme: 2 I. Description A) Phase, solubility, color, odor, shape II. Flame Test A) Orange flame ? Na+ present (possibly K+, NH4+) B) Red flame ? Ca2+ present (no Na+) C) Purple flame ? K+ present (possibly NH4+) D) No change in flame color ? Ca2+, K+, Na+ absent (possibly NH4 present) III. pH Test A) Add a little bit of unknown to a small amount of neutral water B) Fill several vials with test solution and use indicators to determine pH Common pHs for Anions and Cations: pH 1.5: HSO4- present; CO32-, HCO3-, OH- not present pH 2.5: SO42- present pH 3-3.5: Al(H2O)63+ present; CO32-, HCO3-, OH- not present pH 5-6: NH4+ and/or Mg(H2O)62+ present pH 7: Cl- and/or NO3- and/or SO42- and/or K+ and/or Na+ and/or Ca2+ present pH 9-10: HCO3- present; HSO4-, OH-, and Al(H2O)63+ not present pH 10-12: CO32- present; HSO4-, Al(H2O)63+, NH4+ not present pH 13: OH- present; NH4+, Al(H2O)63+, HSO4-, HCO3- not present If unknown is an insoluble compound, use the liquid to test pH pH 7: CaSO4*2H2O pH 9.5: MgCO3 pH 10: CaCO3 pH 10.5: Mg(OH)2 pH 12.5: Ca(OH)2 *Separations are necessary to test for Cations. To Separate, add excess 3-6M
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern