5.Why does adding a salt solution cause soap to precipitate?
458894
This question has been asked and answered before. Check here.\nhttp://answers.yahoo.com/question/?qid=1006032013820
131798
Salt IS a chemical compound. It doens't HAVE chemical compounds.\n\nThe question makes no sense whatsoever. Someone is trying to fool you.
562045
The decrease in temperature decreases the solubility of the solution.  The solution becomes supersaturated and the sugar precipitates out of solution
836118
The salt melts the ice.  The car goes over the water, gets splashed. Salty water wets the car.  Water evaporates leaving the salt on the  car.  Everytime there is some moisture on the air, salt re-dissolves and attacks the metal.  This will continue until you wash your car.\n\nConclusion.  If you leave in snow country where salt si spread wash your car during the winter frequently.
799604
If the ionic compound is soluble, no precipitate is formed.\n\nOn the other-hand, if an ionic compound is not very soluble in the solvent, then it will precipitate out of solution.\n\nFor example, Sodium chloride is soluble and Silver nitrate is soluble, but if these solutions are mixed, some of the Silver ions will react with chloride ions and form solid Silver chloride precipitate.
883409
I will assume that "salt" is referring to sodium chloride, NaCl.  The solubility of NaCl increases with increasing temperature and decreases with decreasing temperature.\n\nSince you are starting with a saturated solution (meaning that it contains the MAXIMUM amount of NaCl at that temperature) and you are cooling the solution to 20oC from 60oC, the cooler solution will not be able to keep the NaCl dissolved and you will observe small crystals of NaCl precipitating from the solution.
127596
Probably because the dye that colors the soap is not a compound that froths and bubbles the same way soap does, if it does at all. It also might be spread out too much as the soap expands into bubbles to be seen clearly.
712912
BaI2(aq) + MgSO4(aq)  --> BaSO4(s) + MgI2(aq)\n\nSo BaSO4 will precipitate.
374138
Need to be more specific in your question.  There are many different types of salts, each with their own densities.
636383
The purpose of adding salts is to neutralize the charge on the sugar-phosphate backbone of the DNA, but ethanol's task is a little more complex than "removing" the water. For a precipitation, you're interested in forming ion pairs between the polyanion (DNA) and the cation (Na+, Mg++, spermidine, protamine, etc). In dilute aqueous solution, DNA and counterions like Na+ and Mg++ are more or less in the free ion form rather than the ion pair form (that is, they are surrounded by one or more layers of water molecules).\n\nWater has a high dielectric constant (e), which from Coulomb's Law tells us that the electrostatic force (F) between two ions of opposite charge is very low in water:\n\nF = (Q1 * Q2)/(e * r2)\n\nwhere Q is the charge on each ion and r is the distance between them. Adding organic solvent(read ETHANOL) *decreases* the dielectric constant of the solution. As e goes down, F goes up and *BANG*, anion and cation form an ion pair and promptly swoon out of solution.
877951
A small amount of sodium hydroxide is probably neutralized in their digestive system.  Plus, if you are adding it to a butter, you may actually be reacting the caustic with ingredients in the butter (fats, fatty acids, etc...) which will just make the butter salty.  Also, caustic soda reacts with CO2 in the air to form Sodium Carbonate pretty readily, which is harmless.  I'd try another "poison".
97980
Barium sulfate will precipitate. The reaction is\n\nCuSO4(aq)+ BaCl2(aq)---> 2CuCl(aq)+ BaSO4(s)
1145145
Dissolved materials that can precipitate out of solution can cause problems with appliances. They are a particular problem with systems that heat water, because this increases precipitation and causes scale. This can reduce efficiency of heating elements, and can block pipes.\n\nHeating systems suffer less, because it is always the same water, so once the solids have deposited out there are no more to add to the scale, and this is very little scale. However, other dissolved materials can cause problems by leading to corrosion.
558485
It is called Total Fatty Matter. It gives the lather producing capacity of the soap. The more it is the good the soap is.
926256
Normally, the soap we used is sodium or potassium salt made from the mixture of a sodium or potassium solution with fat acid.  Therefore, sodium palmitate, for example, is a salt and also a soap we used daily.  When sodium palmitate is dissolved by water, it will ionize into sodium ion and palmitate ion.  Palmitate ion is made out of two parts which is the hydrophobic part and the hydrophilic part.  The hydrophobic part will dissolves in grease or oil but not water, while the hydrophilic part will dissolve in water but not grease or oil.  In short, the hydrophobic part of the ion dislikes water while the hydrophilic part of the ion likes water.  Therefore, the hydrophilic part of the palmitate ion will dissolve in water, reducing or breaking the surface tension of water as the hydrophilic part of the ion forces itself into the neat structure of the water.  Therefore, the neat structure of the water will be broken up, causing the surface tension of water to break up.  For your information, palmitate ion is the one doing all the cleaning, breaking up the dirt on our clothes.  As for detergent, it ionizes into sulfonate ion and has two parts as well.  The mechanism of detergent breaking the surface tension of water is the same as the mechanism of soap.  I hope you understand what I’m saying as I learn all these in a different language.  Sorry if I wrote the wrong terms.
1014526
salts only get into your tap water when there's a problem with your water softener.  it may be turned up too high.
910154
i've never heard of salt cleaning oil stains, and as far as i know it cant, salt won't react with oil, because oil is non polar and salt is polar, you need a polar liquid to dissolve a polar substance and vice versa, \nnow i can tell you how soap or dishwashing liquid cleans oil stains, basically the molecules in soap have 2 ends, one end is polar and the other is non polar, so the non polar end binds to the oil, while the polar end binds to the water and washes it away\n\nhope that helps