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QualitativeAnalysis+
Qualitative Analysis, Cations only
Question | Answer |
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When using sodium hydroxide solution NaOH what effect does it have on calcium, Ca 2+? | When NaOH is added dropwise a white precipitate is formed and when NaOH is in excess the precipitate does not dissolve. |
When using sodium hydroxide solution NaOH what effect does it have on Pb 2+ Al 3+ Zn 2+? | When NaOH is added dropwise a white precipitate forms and when the NaOH is added in excess the white precipitate dissolves forming a colourless solution. |
When using sodium hydroxide solution NaOH what effect does it have on Cu 2+? | When the NaOH is added dropwise a blue precipitate is formed and the precipitate does not dissolve in the excess NaOH. |
When using sodium hydroxide solution NaOH what effect does the NaOH have on the Fe 2+? | When the NaOH is added dropwise a green precipitate is formed and does not dissolve in excess NaOH. |
When using sodium hydroxide solution NaOH what effect does it have on Fe 3+? | A red brown precipitate is formed when the NaOH is added dropwise and when added in excess the precipitate does not dissolve |
When using sodium hydroxide solution NaOH what effect does it have on NH4 +? | No precipitate is formed when the NaOH is added dropwise while on warming a pungent smell is detected and it turns moist/damp red litmus paper blue |
When using ammonia solution or ammonium hydroxide NH4OH what effect does it have on Ca 2+? | There is no effect on calcium 2+ when the ammonia solution is added dropwise. |
When using ammonia solution or ammonium hydroxide NH4OH what effect does it have on Al 3+ and Pb 2+? | A white precipitate is formed when the ammonia solution is added dropwise but in excess the precipitate does not dissolve. |
When using ammonia solution or ammonium hydroxide NH4OH what effect does it have on Zn 2+? | A white precipitate is formed when the NH4OH is added dropwise and in excess the precipitate dissolves and forms a colourless solution. |
When using ammonia solution or ammonium hydroxide NH4OH what effect does it have on Cu 2+? | A blue precipitate is formed when the NH4OH is added dropwise and in excess the precipitate dissolves forming a deep blue solution |
When using ammonia solution or ammonium hydroxide NH4OH what effect does it have on Fe 2+? | When NH4Oh is added dropwise to Fe 2+ a green precipitate forms but when added in excess the precipitate does not dissolve. |
When using ammonia solution or ammonium hydroxide NH4OH what happens to Fe 3+? | A red-brown precipitate is formed when the ammonium hydroxide is added dropwise but when it is added in excess the precipitate does not dissolve. |
When using potassium iodide solution, KI, what happens to Pb 2+? | A bright yellow precipitate is formed when the potassium iodide solution is added to the lead 2+ solution. |
When using potassium iodide solution, KI, what happens to Al 3+? | No precipitate is formed when the potassium iodide solution is added to the aluminium 3+ solution. |