- #1
- 715
- 2
Pure copper metal is orange (or pink after being anodized), copper hydroxide is blue, copper oxide is black. So then why is the statue of liberty green?
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Discussion Overview
The discussion centers on the color of oxidized copper, specifically addressing why the Statue of Liberty appears green. Participants explore various chemical compounds and oxidation states of copper that may contribute to this coloration, including references to other forms of oxidized copper such as those found in old pennies.
Discussion Character
- Exploratory, Technical explanation, Conceptual clarification, Debate/contested
Main Points Raised
- Some participants note that pure copper is orange or pink when anodized, while oxidized forms like copper hydroxide are blue and copper oxide is black.
- Others suggest that the green color results from oxidation processes, with one participant mentioning that they have observed copper turning green.
- Several participants reference the green color of old pennies as a similar phenomenon.
- One participant proposes that there are multiple oxidation states of copper, with at least one being green.
- Another participant speculates that the green color of the Statue of Liberty could be due to copper carbonate, mentioning the role of carbonic acid formed from rain reacting with copper.
- It is mentioned that sulfates and acetates can also cause copper to turn green.
- A link to a Wikipedia page on copper carbonate is provided for further reference.
Areas of Agreement / Disagreement
Participants express various hypotheses regarding the chemical processes involved in the green coloration of copper, but no consensus is reached on a single explanation or the specific compounds responsible.
Contextual Notes
Some claims depend on assumptions about chemical reactions and the specific environmental conditions affecting copper oxidation, which are not fully detailed in the discussion.