Why does the volume of water increase on freezing?
The water molecules align in specific order when making the crystals in ice. This order takes up more volume than the random orientation they can achieve in the liquid phase. In other words, the molecules can snuggle closer together as a liquid compared to a solid.
What happens if a given volume of water is cooled from 4C to 0C?
The answer to your question is: - the volume INCREASES - the mass remains STABLE Explanation: 4 degrees Celcius is the point where water has the lowest volume. Either above or below this temperature, the volume is always higher than at 4 degrees Celcius. However, mass has nothing to do with temperature. Mass is basically just the amount of atoms, not how much space they take.
When gas dissolves in water at high pressure, will the the volume of water increase simultaneously?
yes.. probably not anything noticable. ******* Let's think about the maximum case if we assume the gas is at 1atm and say 298K PV = nRT PV = (mass/mw) RT mass = mw x PV/(RT) = 4.008g/mole x 1atm x 0.200L / (0.08206 Latm/moleK x 298K) = 0.0327g if you liquify all that He ... density of liquid He = 0.125 g/mL so that 0.0237g H2 x (1mL / 0.125g) = 0.2mL if you magically add 100mL of H2O and 0.2mL of He.. you're volume will be probably be somewhere between 100mL and 100.2mL depending on the density. ********* but.. you still have some He in vapor phase because you have 5Mpa of pressure You've probably changed the temperature and therefore changed water density etc... so YES the volume will change NO.. I don't think you'd notice it.
Does the volume of water increase, decrease, or remain the same?
due to the change in temperature, the density changes (remember that ice is less dense than water and thanks to that, it floats) [The density of an object is defined as mass per unit volume. its directly related to volume so volume changes as well] mass must always stay the same, Sense the quantity didn't change, but what might change is its weight, but i dunno about that. . . the volume also changes, when it froze it became a solid. the molecules are now arranged in a more compact way. there is less entropy(disorder). there are many ways to explain why volume changes, but remember that due to molecular movement, at higher temperature molecules move more freely covering a larger ammount of space, therefore increasing in volume. at lower temperature there is less molecular movement, so the volume decreases
Fluids - density question?
A lock is a body of water contained between 2 sets of openable gates, used to transport cargos by water using different levels, like the Panama Canal. Considering an upstream direction, the vessel is placed in the lock, when the upstream gates are shut. The downstream gates are then closed, and water from upstream is allowed to flow through a pipe into the lock. It continues to flow until the water level in the lock is at the level of the upstream water, at which time the upstream gates are opened, and the vessel continues on up the stream, now elevated to a new level. Going downstream is a reversal of the above sequence, and the vessel continues lower. A barge is just a large, flat bottomed boat propelled by a tug, used to transport goods on water. The lock area is (64 x 23.5) = 1,504m^2. When the steel is placed on the barge, an extra weight of water equal to the weight of the steel is displaced. So weight displaced = 2,750,000N. That's a mass of (2,750,000/9.8) = 280,612.24kg. The volume of the water displaced = (280,612.24/1,000) = 280.61m^3. (280.61/ 1,504) = height increase of 0.1866 metre in water level. When the steel is pushed into the water of the lock, it only displaces its own volume of water. So, the water level increase will fall. (280,612.24kg./8100) = 34.6435m^3of steel. (34.6435/1,504) = water height of 0.023 metres. Difference in water height produced = (0.1866 - 0.023) = 0.1636m. between the steel being on the barge and the steel being in the water.