4. For a solution containing at least one of the cat- ions involved in this experiment, answer the following questions.
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4. For a solution containing at least one of the cat- ions involved in this experiment, answer the following questions.
4. For a solution containing at least one of the cat- ions involved in this experiment, answer the following questions. (1) A solution is acidified to pH 0.5, and H2S is added. A dark precipitate results. Which cation(s) may be present? (2) KOH is added to the precipitate from (1). The supernatant liquid is separated from the dark precipitate and tested with HCIHS. A colorless solu- tion results, with no precipitate. Which cation(s) may be present? (3) The remaining precipitate from (1) is treated with dilute HCI. The supernatant liquid is tested with NH, and H,S. A yellow precipitate results. Which cat- ion(s) may be present? (4) The precipitate left from the first step in (3) is dissolved in HNO,, and the resulting supernatant liq- uid is treated with NHg. A blue supernatant liquid re- sults, with no precipitate. Give the identity of all Group II cations present in the original solution
Biºco? Cu? Snci, 2- HẠS, DH 0.5 supernatant liquid residue (centrifugation) Discard if only Group Il lons are present. Retain it Group tll & IV lons are present. Bi S cas, (yellow- orange) Cus, (black- brown) Sns (yellow) (black) 3M KOH supernatant liquid residue (centrifugation) Sn(OH)? Cas, BigSs. Cus (yellow) (black) (black) 6M HCI Has supernatant 6MHCI liquid residue (centrifugation and decantation) (CaCu?.HS Bi Sy. Cus (colorless) (black) (black) SnSz (yellow) Cas (yellow) 6M NH Hys 6M HNO, theat) supernatant liquid residue (decantation) Biº, Cu(H20).** (blue) (yellow) 6M NHS supernatant liquid residue (centrifugation and decantation) [Cu(NH3)* (dark blue) BI(OH) (white)