| index item |
standard |
| Assay(ZnO) |
99.0%-100.5% |
| identification |
A:When stongly heated,it assumes a yellow color |
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that disappears on cooling |
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B:Asolution of it in a slight excess of 3N |
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hydrochloric acid responds to the tests for |
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Zinc<191> |
| Alkalinity |
Mix 1.0g with 10ml of hot water,add 2 drops of |
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phenolphthalein TS,and filter;if a red color |
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is produced.not more than 0.30ml of 0.10 N |
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hydrochloric acid is required to discharge it |
| Loss on ignition |
not more than 1.0% |
| As |
not more than 6ppm |
| Carbonate and color of solution |
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Mix 2.0g with 10ml of water,add 30ml of 2N |
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sulfuric acid,and heat on a steam bath,with |
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contant stirring;no effervescence occours |
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and the resulting solution is clear and colorless |
| Lead(Pb) |
Add 2g to 20ml of water,stir well,add 5ml of |
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glacial acetic acid,and warm on a steam bath |
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until solution is effected,the addition of 5 |
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drops of potassium chromate TS produces no |
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trubidity or precipitate |
| Iron and other heavy metals |
Cooled 5ml portions of the solution obtained |
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in the test for Carbonate and color of solution |
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yield white precipitates with potassium |
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ferrocyanide TS and with sodium sulfide TS |
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