Search results
Results From The WOW.Com Content Network
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
The cations and anions are shown by separate ternary plots. The apexes of the cation plot are calcium, magnesium and sodium plus potassium cations. The apexes of the anion plot are sulfate, chloride and carbonate plus hydrogen carbonate anions. The two ternary plots are then projected onto a diamond. [3]
Relative radii of atoms and ions. The neutral atoms are colored gray, cations red, and anions blue. Ions may be larger or smaller than the neutral atom, depending on the ion's electric charge. When an atom loses an electron to form a cation, the other electrons are more attracted to the nucleus, and the radius of the ion gets smaller.
Cations are positively (+) charged ions while anions are negatively (−) charged. This can be remembered with the help of the following mnemonics. Cats have paws ⇔ Cations are pawsitive. [27] Ca+ion: The letter t in cation looks like a + (plus) sign. [28] An anion is a negative ion. (An egative ion ⇒ Anion). [29]
Cations are plotted in milliequivalents per liter on the left side of the zero axis, one to each horizontal axis, and anions are plotted on the right side. Stiff patterns are useful in making a rapid visual comparison between water from different sources. An alternative to the Stiff diagram is the Maucha diagram.
Cations and anions are measured by their ionic radius and they differ in relative size: "Cations are small, most of them less than 10 −10 m (10 −8 cm) in radius. But most anions are large, as is the most common Earth anion, oxygen .
Ions in salts are primarily held together by the electrostatic forces between the charge distribution of these bodies, and in particular, the ionic bond resulting from the long-ranged Coulomb attraction between the net negative charge of the anions and net positive charge of the cations. [18]
In inorganic chemistry, Fajans' rules, formulated by Kazimierz Fajans in 1923, [1] [2] [3] are used to predict whether a chemical bond will be covalent or ionic, and depend on the charge on the cation and the relative sizes of the cation and anion. They can be summarized in the following table: