i know that iron(II)hydroxide is brown solid,how about iron(III)oxide?
The colour of iron oxides vary a lot.
Iron(II) hydroxide in its purest form is white (even though the handbook says it is pale green). We almost always see it in the test tubes as a dirty green. The colour is due to partial oxidation of Fe(OH)2 to Fe(OH)3.
Rust is basically Iron(III) oxide, and is reddish brown to black.
Iron(III) oxide, also known as ferric oxide or rust, is a compound with a reddish-brown appearance. It is a common oxide of iron that forms when iron reacts with oxygen in the presence of moisture or water. The reddish-brown color of iron(III) oxide is due to the presence of iron in its +3 oxidation state.
If you want to confirm the color of iron(III) oxide, one way to do so is by conducting a simple experiment. Here's how you can proceed:
1. Begin by obtaining a small amount of iron or an iron-containing compound. Iron nails, steel wool, or iron filings are readily available sources of iron.
2. Place the iron or iron-containing compound in a container that can withstand high temperatures, such as a ceramic crucible.
3. Heat the iron under controlled conditions in the presence of air. This can be done on a laboratory burner or by using a hot plate.
4. As the iron reacts with oxygen in the air, it will form iron(III) oxide. Initially, the oxide may appear black, but when it cools down, it will turn reddish-brown.
5. Allow the iron to cool and carefully observe the resulting iron(III) oxide. Note its reddish-brown color, which is characteristic of this compound.
By conducting this experiment, you can personally observe the color of iron(III) oxide and verify that it is indeed a reddish-brown solid.