how can you say different liquids have different rates of expansion for the same rise in temperature
Answers
Explanation:
Different liquids have different rates of expansion. I think we can fairly say that (most) substances expand when heating because they vibrate more, because they have more kinetic energy, so there's a pushing force between molecules. For almost the same reason, gasses expand.
Explanation:
Different liquids have different rates of expansion.I think we can fairly say that (most) substances expand when heating because they vibrate more, because they have more kinetic energy, so there's a pushing force between molecules. For almost the same reason, gasses expand. I suppose you could invoke some entropy arguments but I don't think it's really necessary to do so. In condensed phases (liquids, solids), intermolecular forces are very important to determining bulk properties, and at higher temperatures these forces will be weakened. (Well, weakened, plus there is simply the fact that there's a lot more thermal energy around to break them apart.) This will also, I think, tend to favor expansion.
So what types of substances are more likely to have larger thermal expansion coefficients?
My first thought is that thermal expansion will be larger in (a) smaller molecules and (b) molecules that have weaker intermolecular forces. Smaller molecules because for a certain volume of liquid, there will be more molecules when molecules are smaller, so there will be more particles (if you want to think of them that way) pushing each other apart. (That is to say, I'm thinking the volume of actual molecules doesn't change as temperature is raised as much as the volume of the space between molecules does.) Wrt to strength of intermolecular forces - if the forces are weaker between molecules, they won't be able to stick together as well when the temperature rises, so molecules with weaker intermolecular forces should expand more readily as temperature raised.
So, that was my prediction. The next step is to look for data. Sadly, I had a hard time finding good tables of data. Even the CRC wasn't very helpful.... or at least, I didn't see them in there.
Pl mark it the brainielist