Assume that you failed to remove air bubbles that were trapped in the stem of your pipet before transferring the liquid for your density determination. Will your calculated density be too low, too high, or unaffected by this? Explain why.
209105
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.
76423
ehm...aren't you suppose to substact 200psi of residual pressure from that 1300psi 1st?  giving you 265.7 minutes left.
287763
I thing you are referring to surface tension pulling the water up the tube. The water can't be pulled past the end of the tube since there is no tube after that to pull on. In other words the water doesn't know the tube is too short until it gets to the end.
458966
I'll agree that you need help.  Density is mass/vol.  You've given the density, you need another value to calculate the remaining value.
426972
Pressure and volume are inverses of each other and therefore you can't in the first place say they are at constant pressure unless they were in the same container (When they do mix).. so when they are separated, you can't have the same pressure at different volumes. Though your experiment shows the achievement of equilibrium of high to low pressure, as the bigger one gets bigger (right?)...\n\nAnyways, finding an inexpensive experiment (on the web) is really difficult.  Dalton's law can be used as you probably know by collecting water over gases (which requires some lab equipment and some chemicals not readily available so to say) and also has an application in scuba diving.  I'll ask someone for you that I know... Can you give me 'till Monday or Tuesday to get a good answer for this or when does your presentation have to be done?
457398
I've "witched" water before, but it is a questionable method.  I got 2 two foot long bronze brazing wires from a welder, bent them into equal sized "L"s....not everybody can do it, but you can try it over municipal water lines to see if it works for you.  I am a scientific person generally, but it does work...there is something to it.  be careful to hold them lose but level...go back and forth different directions...if you get a hit, try it from a different direction...don't let your sub-conscience mind take over and try to fool you.  there are times for me that I could not stop the crossing of the wires the indication was so strong.  The method is questionable because there is no depth meter on the wires and it could be anything, like differential density of the sub ground causing it...it could be water or something else.  I have heard of "witching" graves because of the differential density I suppose.
82223
Distill the water. The WATER comes out of the tubes, not the salt.\n    As for testing, just drink a little of it. Do you *LIKE* it?\nNo? Well you better make sure that you don't put it back in the same cup you used for collection.\nOK the water will still pass an electric current through it if it has any impurities. Completely pure water will not.\nUnless you use more than around one volt, in which case the bubbles you see escaping will be hydrogen and oxygen. That means you've gone too far with the testing part.
446453
Solid - take a sample of the solid.  Weigh it. Fill a graduated cylinder with water. Put the sample in the water. Measure the change in volume of the water. This change in volume is the volume of the sample. Now you have the measurements you need to calculate the density.\n\nLiquid - take a known volume of liquid and put into a container of known weight. Weigh the liquid and the container. Subtract the mass of the container.  This is the mass of the liquid. Now you have the volume and mass of the liquid you can calculate the density.\n\nIf you need to be really precise I would suggest taking the temperature of the liquids.
405872
I did this a long time ago at a science fair.  You need a small glass tube, like a test tube, but not too big.  Put a weight around the opening so it will float with the open end down.  The tricky part is to adjust the weight in the tube to it just floats.  Another way is to adjust how much water is in the tube when it is floating.  Put it in a plastic bottle with enough water to allow for submerging and surfacing.  (They don't like the work "sink" on submarines.)  To make the tube submerge, squeeze the bottle.  This compresses the air inside the tube.  The air takes up less space, provides less floatation and it submerges.  Release the bottle and the tube rises again.  It was acutally a lot of fun when I did it.
620399
Take a look at your sludge under a microscope. If the bacteria create too long fibres, the sludge will capture gas bubbles and refuse to sink even with strong coagulating agents. \n\nYou might have to restart the biological stage of your treatment plant with a new culture. Check with your service specialists first, though.
409811
I don't think halving it makes any difference because don't you have to half the mass because you half the stopper (therefore it would be half the grams making it 7.5 grams) if thats so you would divide 7.5 by 2.5 cm since it probably would only rise half the distance as it would normally and you still get the same density of 3.
147593
Assuming the container was rigid (like a tin) and completely empty (i.e., a vacuum) before you put the air in, the container would be full, because gasses expand to fill the space that's available, so the container would hold 2 litres of air that would be less dense. \n\nIf the container was flexible (like a balloon), the air pressure outside it would collapse/squash the container until the pressure inside was the same as the air pressure outside, so it would be still be full, but it would contain 1 litre of air that was at normal density.
513350
I will look at it from a different angle.\nConsider the equation of state,\nPV=MRT\nExpansion through a nozzle causes the\npressure to drop and volume to increase \nbut not as compared to drop in pressre. \nThe net effect is that product PV reduces.\nM the mass is not changing. R is the gas \nconstant. So T[temp in absolute] has to drop.
467153
Actually, it's the volume of the headspace (the empty space between the liquid and the top of the can.  In some circles, this is known as "ullage".  Search on that.  Given enough ullage, the pressure will be lower.
35731
This can be done with a density gradient column.  It is made of 2 fluids that are carefully mixed so that the density of the mixture varies from the top of the container to the bottom.  An object will then come to rest where its density matches the mixture.  This is actually a very accurate way of determining the density of materials.  However, over time the fluids in the column mix by diffusion and will eventually cause the suspended objects to sink or float.
387481
Hmmmm...interesting...I didn't think you could really do that experiment WITHOUT making a mess! :)  (And isn't mess-making, next to bang-making, one of the main attractions of chemistry?)  I guess you could point the bottle away from you, at an angle, pop the Mentos into it with your fingers, then pull your hand away really quickly.
589568
That may depend on your application.  The pressure drop will depend on whether you are filtering gas or liquid and whether you are interested in the pressure drop of new filter samples or filters in use as they become clogged.  Flow rate will also increase pressure drop.\n\n\nFor example, if the filter is installed at as joint in a round horizontal pipe, and the flow is liquid (water?), and the pressure is relatively low, you can attach vertical plastic tubes with pipe fittings upstream and downstream of the filter.  If the water rises say one foot higher in the upstream tube than the downstream tube, the pressure drop across the filter is 12 inches w.g. (water gage).  If the pressure is too high for plastic tubes (where about 15 psi would require 34 foot high tubes), you can attach pressure gages to the pipe fittings and compare their readings or install a differential pressure gage across the fittings to directly read the pressure drop.\n\nIf the flow is a gas (air?), flowing through a duct, you can install a clear plastic "U" tube partially filled with water (and food coloring?) across fittings upstream and downstream of the filter to measure the pressure drop in inches w.g. or use a sensitive differential pressure gage.  Hope that helps a little.