Why do some things dissolve in water and some things don't?

Answer 1

If the compounds are liquids, here is what determines water solubility: Water molucules have polarity. The solubility of a liquid is determined by its polarity. Polar substances often contain OH-, SH- and NH2- groups. The more of these groups a liquid contains, the more water-soluble it is. These groups can form hydrogen bonds with water, which are very strong. Because these bonds are very strong a molecule that contains more OH-, SH- and NH2- groups is more water-soluble. If the compound is a gas, Henry's Law determines the solubility of gasses in water. This law links the partial pressure of a gas to its mole-fraction in the liquid phase, and thus declares how much of the gas is dissolved. According to calculations from Henry's Law oxygen is more water-soluble than nitrogen.

Henry's Law describes as follows:

P = H * x

In which p is the partial pressure of a gas, H is a constant that differs for each gas and x is the mole-fraction of the gas in the liquid phase.

Some gasses have a specific way of acting when they are dissolved.

Answer 2

Some substances are soluble. This means they are able to dissolve into other substances. Sugar, for example, is soluble in water, however, vegetable oil is not. This has to do with their chemical makeup.

Answer 3

Water is slightly polar, which means that one part of the molecule (the O part) is slightly negatively charged, and the other part (the H part) is slightly positively charged. Since opposite charges attract each other, water can pull apart other ionic or polar compounds or ions which also have charges by having the positive parts of them move toward the O of the water and the negative parts of them move toward the H, or by the water molecule slipping inside and separating these charged parts of the compounds or ions. This dissolves them, merely by separating parts of the compounds so that big groups of their molecules or atoms aren't together anymore. An example of this is table salt, sodium chloride (NaCl). The sodium part (Na) is positive, and will be surrounded by the O's of water, and the Chlorine part (Cl) is negative, and will be surrounded by the H's of water. Separating the Na's from the Cl's makes salt dissolve in water. Other compounds and molecules are not polar or ionic. Since they don't have polar charges on them, the slight charges from the water don't pull them apart, and they don't dissolve in water.

Answer 4

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Answer 5

Substances that are polar are soluble while substances that are non-polar are insoluble

Answer 6

because the solvent temperatures are different

Answer 7

because some things do not have the substance to dissolve. while others can. Such as, A lifesaver, it can disolve but a piece of meat cannot.