Silver Oxide: Silver Nitrate Precipitated with Solution of Potassa (USP 1870)

Silver oxide is a heavy, dark brown powder, and heating it to about 250 °C leaves pure silver. Potash added to a silver nitrate solution throws it down, and washing leaves potassium nitrate behind in the water. Source: US Pharmacopoeia 1870, as quoted in the US Dispensatory (1907), Argenti Oxidum. Not given here: the strength of the solution of potassa; ours: potassium hydroxide in distilled water. Silver nitrate stains and burns skin: gloves and goggles. Picture drawn by Youblob.

مبتدئ

1 day

التعليمات

Dissolve 4 troy oz silver nitrate in half a pint of water

Dissolve 4 troy ounces of silver nitrate in half a pint of distilled water. Silver nitrate stains and burns skin: gloves and goggles.

المواد لهذه الخطوة:

نترات الفضة4 troy oz

ماء مقطر0.5 pint

الأدوات المطلوبة:

ميزان ذو كفّتين

كأس زجاج بوروسيليكاتي

قضيب زجاج بوروسيليكاتي

قفازات نتريل

نظارة واقية من رذاذ الكيماويات

Add solution of potassa while it still precipitates

Add solution of potassa, about a pint and a half or as much as needed, for as long as it still throws down a precipitate. Ours: potassium hydroxide dissolved in distilled water; the USP strength is not given here. Potash free of carbon dioxide keeps out silver carbonate.

المواد لهذه الخطوة:

هيدروكسيد البوتاسيوم1 as required

ماء مقطر1.5 pint

الأدوات المطلوبة:

كأس زجاج بوروسيليكاتي

قضيب زجاج بوروسيليكاتي

قفازات نتريل

نظارة واقية من رذاذ الكيماويات

Wash, dry and store in the dark

Wash the precipitate again and again with water until the washings are almost tasteless. Dry it and keep it in a well-stoppered bottle away from light. Ours: filter paper, and a low oven, well below the 250 °C at which it breaks down to silver.

الأدوات المطلوبة: