RogueRose
International Hazard
Posts: 1590
Registered: 16-6-2014
Member Is Offline
|
|
Cu + H2SO4 + heat = black precipitate & a Sulfur oxide(s) - where is the CuSO4?
I tried adding small clippings of wire (10gr of 18-20ga & 2-3mm length) to 93% H2SO4 as well as 31% then heated. When heated to boiling the
concentrated turned black pretty quickly and emitted a strong sulfur gas whether it is dioxide or triodixe or both, IDK, but it looks like CuO was
produced very efficiently. The diluted acid acquired a grey tint although remains clear.
I've seen a lot of videos where this reaction creates CuSO4 and know that this works when adding H2O2.
Does the Cu act as a catalyst that breaks down the acid. Wiki states that CuSO4 is made industrially by heating the Cu or Cu oxides in hot
concentrated acid. Was too much heat used maybe, that doesn't allow the formation of the sulfate?
|
|
DraconicAcid
International Hazard
Posts: 4308
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
I suspect you'll get CuSO4 in more dilute acid, or under less-than-boiling conditions.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
Amos
International Hazard
Posts: 1406
Registered: 25-3-2014
Location: Yes
Member Is Offline
Mood: No
|
|
Use dilute acid, closer to 10-20%, and use a wide shallow container so it can take up plenty of oxygen to serve as your oxidizing agent.
|
|