posted by Soonjung on .
The iron in steel has a density of 7.86 g/cm3. When iron rusts, it forms hydrated Fe2O3 that has a density of 5.12 g/cm3. What happens to the volume as iron rusts?
Like does it expand? contract? stay the same? expand then contract? <-- that is my question
I want to say that the volume stays the same because density = mass/volume and since the volume won't really change? It would only be the mass that is changing while it rust?
I am confused if that makes any sense. But that is what my logic is for this. So if someone can care to explain what happens to the volume as iron rust it would be great.
As you point out, the question is silly.
The density of rust is less than the density of iron, so for the same mass, rust has more volume.
example: The density of sulfur is 2.07g/cm^3. The density of sulfur dioxide is .0014 g/cm^3. what happened to the volume as sulfur burned? You are correct, the question is silly and ill-conceived.