Why does a cartesian diver sink when the bottle is pressed? chemistry?
487982
I'd say physics rather than chemistry.  When you squeeze a bottle full of water containing a gas-filled "diver", the water is not compressed.  Only the gas in the diver compresses causing the diver to displace less water.  The cartesian diver is carefully made to be just barely buoyant, so when compressed its reduced displacement causes it to sink.
49373
When you put an object in water--or any other fluid that is minimally compressable, like milk or oil or alcohol--the object takes up space.  Especially for fluids that are very runny--like water, in contrast to, say, old crank-case oil--the fluid will fill every nook and cranny available.  Since the water, or other non-compressable fluid, has to move out of the way for the object put in it, the apparent rise in the total volume of water-plus-object is due to the volume of the object.\n\nOf course, if the object FLOATS in water, you're in a whole new situation: the object will displace (move aside) exactly the amount of water that weighs what the object does.  That's a whole different discussion!
48352
It's a sealed room with high barometric pressure.  Sometimes if divers come up too soon, they get a condition called "the bends" in which nitrogen dissolved in the bloodstream starts to come out as bubbles of gas.  (Think of how bubbles come out of soda when you lower the pressure by opening the top.)  So the divers can be put in a hyperbaric chamber, where more of the gas will stay dissolved and the pressure can be lowered gradually.
555685
the liquid evaporating
1149664
An object sinks when it's weight exceeds the weight of the amount of water displaced by it's volume. The density of pure fresh water is 1kg/l. Assuming the the bottle must be completely full to contain 2l of water, a 2l bottle of water will weigh 2 kg and displace 2 kg. It will have neutral buoyancy. The bottle itself will displace more than it weighs, so the bottle will float.
605564
Water doesn't slow down gravity. Gravity always pulls things down at roughly 9.8 m/s^2 (at most places on Earth, anyway). What happened, though, is that the water slowed down the desent of the coins. Remember, water is a molecule. When gravity pulled the coins down through the water the water molecules pushed back up against the coins. Its Newton's law, "for every action there is an equal and opposite reaction." Air actually works the same way. Its called terminal velocity. If you jumped out of a plane you can only fall so fast before the force of the air molecules acting against gravity equals the downward force of gravity, thereby keeping you from accelerating downward to a faster speed.\n\nNow, as for why one hit sooner then the other, that's because of how they fell. If the coin fell flatwise on the water it falls slower because there is more surface area of the coin in the way of the water. If the coin falls on its edge there is less surface area of the coin to meet the opposing force of the water and, therefore, less resistance (although the coin will flop around and turn from the force more readily). Actually, predicting a coin's free movement through a liquid is quite difficult and involves a lot of fluid dynamics and center of mass stuff.\n\nFor short distances, though, you can generally fake a rough estimate by simplifying math. You know those things with a fishbowl and a shotglass that most places like Perkin's have? Where if you drop a quarter into the glass you get a free cookie or something? Most people drop the coin edgewise and then wonder why the coin misses. The best way to do it is drop the coin in flat over the glass because the force acting against the coin is more balanced and less prone to exerting a torque the the coin as it falls. Try it sometime and see for yourself.
801652
This is really a trick question.  The contents inside a closed (pressurized) can or bottle contains two phases.  The lower phase is a liquid solution and the upper phase is pressurized gas containing a high percentage of carbon dioxide (this is a gas solution).\n\nWhen the container is opened, the pressurized gas excapes into the atmosphere and upon doing so allows a change to take place in the solution below.  The chemical change is:\n\nH2CO3 (aq) --> H2O (l) + CO2 (g)\n\nThe gas bubbles of carbon dioxide form inside the liquid solution, turning it into a mixture (I doubt that the term mechanical has much meaning here).
493932
Actually, the CO2 is not in liquid form.  The CO2 molecules are trapped in the liquid.  That is why you can actually see the CO2 rise to the top of the soda.\n\nWhen you shake the bottle, you are releasing a large volume of the CO2 molecules.  However, you might wonder why the pressure just stays the same since nothing has been added to the bottle.  What's the difference between the CO2 molecules being in the liquid or in the air space above it?  Quite a bit of difference.\n\nWhen the CO2 is in the liquid, it is not able to expand like  a gas.  It does take up space in the liquid, but the liquid keeps it in a more confined space.  When the CO2 escapes the liquid, it now fills the air space as a gas pushing in all directions.  It is now able to expand like a normal gas which is why you get more pressure.
372889
Every body that is in a fluid, or it is floating on the surface, or is sunk to the bottom loses an equal ammount of weight as the weight of the displaced fluid by the volume of the body.\n\nThe force that makes body's float or makes them lighter in a fluid (for ex. water) is called Archimed's force or Archimed's principle.\nIf this force is grater then the weight of the body (G=m*g) then the body floats on the surface.\n\nArchimed's force is greater if the density of the fluid is bigger. Oil has the density of 900 g/cm3 and water has the density of 1000 g/cm3. Because the reason why the objects are floating in oil and in water is of same nature, floating on oil is similar to floating on water.\nBut water has a bigger push force then oil.
271065
When in the bottle or can the solution is in equilibrium with the partial pressure of C02 equal to the pressure in the can. When the can is opened the pressure in the can drops (the ffffft or hiss sound you hear) and now the partial pressure of C02 in the soda solution is greater than the atmospheric pressure. This results in C02 coming out of solution, which causes bubbles to form. The bubbles represent a separate phase, which is a heterogeneous mixture rather than the homogeneous mixture prior to opening.\nNote that the CO2 levels does not completely equilibrate upon opening. Once the solution has come nearly to equilibrium (re CO2), the soda is said to have 'gone flat' and is no longer fizzy.\n\nI'm not sure the presence of oxygen has anything to do with this phenomenon.
634175
It´s not quite clear to me what you are looking for, but here goes....\n\nThe air pressure goes down with the height in the atmosphere. In a gas mixture the molecules are free to roam where they can but under the influence of gravity they stick mainly close to the earth. The pressure drops by about 10% over the first kilometer and is about a third of that at groundlevel at the top of the Mount Everest. The decrease is exponential and the gradient depends on the average velocity of the molecules (a few hundred meters per second).\n\nIn the ocean pressure increases linearly with depth approx. 1 atmosphere each 10 meters. The reason is that the weight of the upper layers presses on the lower layers of a liquid.   \n\nJess knows somewhat more.
773220
When push squeeze the bulb (this is the force), you exert pressure EVERYWHERE in the dropper, (upwards, downwards, etc), so the liquid in the medicine dropper it forced to come out since in the increase in pressure is applied everywhere,\n\nThis is known as pascal's principle
360266
Not trying to get some help with a chemistry homework problem, are you?\n\n\nOkay, my guess is that the molecules of one of the liquids fit into the "gaps" between the molecules of the other.  Kinda like mixing a quart of pebbles with a quart of bigger rocks.  Since some of the pebbles with fit between the bigger rocks, the combined volume will be noticeably less than two quarts.
630018
When you softly place a pin onto the surface of water (horizontally) it doesn't sink because the weight of the pin is balanced by the upward (vertical) component of surface tension. When you add a detergent powder it reduces the viscosity of water and hence the upward force due to vertical component of surface tenbsion decreases and hence it sinks.
462517
If there are bubbles of air then you will have less liquid than you are intending to have. Assuming you are calculating density via measurementof mass then the mass you get will be less than it should be for that volume of that liquid. As a result the calculated density will work out lower than it should do.
116754
In a bottle of softdrink carbonic gas is filled under pressure. So you get the bubbles when you open it. The pressure decreases in the bottle when you open it and so the volume increases.\nIt's due to Volume to Pressure's Inverse Proportionality.
93225
The gas is under pressure, so when you press the nozzel the liquid ....mmmmmm better a picture than words..\n\n http://www.aerosol.com/