If I took an empty measuring cup and added ice cubes such that the level of the ice does not pass the “1 cup” line. Then, I added water to fill in the empty spaces. Volumetrically, how much water will I have when the ice melts? (For sake of argument, the ice actually stuck to the bottom. It did not float over the 1 cup line, but I don’t think that would matter if it did float to the surface.)
Since water expands when freezing, I assume the final volume of the ice (once melted) will be less than the original volume of the ice. In other words, I assume it must contract when melting. In short, I will have 1 cup or less of liquid.
Assuming you ice is at a temperature of less than 0 deg celcius. And you added water with temperature greater than 4 deg celcius. And assuming you measured this total volume and compared it to the volume when ice just melted completly (that is the water is at 0 deg celcius), u’ll see a slight decrease in volume - thats it.
For sake of argument, the ice actually stuck to the bottom. It did not float over the 1 cup line, but I don’t think that would matter if it did float to the surface.
It does matter. Unrestrained, ice floats, with about 10% of it above the surface. If the cup were full of floating ice and water, with the water level at the one-cup line, the water level would still be at the one-cup line (ignoring tiny temperature corrections) when all the ice had melted.
By keeping the ice totally below the surface, you are displacing volume with the portion of the ice that is normally above surface-level. When all the ice has melted, the total level will be lower than when you started. To calculate the precise level, one would need specific measurements of the amount of ice and the amount of water in a given mixture.
Yeah, there’s a relatively big decrease jump in density going from 0 degrees water to 0 degrees ice. If the cup were packed nearly completely full of ice, and you added water to cover it, up to the 1 cup line, according to Gary T’s 10% figure, you’d end up with just a little more than 7 ounces, instead of 8.
Note: if the ice is free to float, even if it is a mass of cubes, the level will not appreciably change (as per GaryT’s post). Only if the ice is prevented from floating freely would the naked eye be able to detect a difference afterwards.
I saw this on Mr. Wizard one time. He filled a glass with ice almost to the top, then filled it completely with water. He even used an eye-dropper to fill the glass to the point that there was no way to get a single additional drop in the glass.
Then, hours later, the ice had melted and the glass was still just as full as before, but hadn’t over-flowed.
IIRC, Mr. W’s explanation was that ice expands as it freezes, but the melting ice adds more water to the glass in such an amount to just about even the whole thing out…
