Main article: Ion
An ion is a charged species, an atom or a molecule, that has lost or g
ained one or more electrons. Positively charged cations (e.g. sodium cation Na+) and negatively charged anions (e.g. chloride Cl−) can form a crystalline lattice of neutral salts (e.g. sodium chloride NaCl). Examples of polyatomic ions that do not split up during acid-base reactions are hydroxide (OH−) and phosphate (PO43−).
Ions in the gaseous phase are often known as plasma.
An ion is an atom or molecule with more or less electrons than usual, giving it a positive or negative electric charge. Because an ion "wants" to become neutral by acquiring or losing additional electrons, it has interesting chemical features. Ions usually come in the form of solutions. There are three types -- anions, which are negatively charged, cations, which are positively charged, and radicals, or radical ions, which are highly reactive due to having a large amount of free electrons.
An ion solution is typically created when certain molecules, such as salt, are dissolved in water. The interactions between the solute and solvent molecules disassociate weakly-bonded molecules, like salt, into two or more ions. When salt is put into water, it breaks into sodium and chloride ions, both of which are essential to human life. If a person is deprived of salt for too long, they will eventually die. Other life-essential ions (called electrolytes) are potassium (K+), calcium (Ca2+), magnesium (Mg2+), hydrogen phosphate (HPO42−), and hydrogen carbonate (HCO3−).
Other ion solutions besides dissolved salts are acids and bases. For instance, hydrochloric acid is formed when hydrogen chloride is dissolved in water. The hydrogen chloride breaks into two ions, H+ and Cl−. The H+ reacts with water to produce H3O+, hydronium ion, while the chlorine remains as a chloride ion. Because the ionization process is complete, hydrochloric acid is called a strong acid. The strength of acids is measured by how many H+ ions they have -- hydrochloric acid many, so it is very acidic. In fact, hydrochloric acid can dissolve through glass and all metals except iridium, though its corrosion speed is slow.
Another category of ion solutions are bases. Instead of being measured by the concentration of hydrogen ions, a base is measured by its concentration of hydroxide ions (OH-). One example of a base is potassium hydroxide, which is the chemical precursor of most soft and liquid soaps. When dissolved in water, potassium hydroxide produces a strong alkali solution. An alkali is a type of base. Potassium hydroxide has a number of interesting chemical properties -- one of them is its hygroscopic (water-attracting) nature, which makes it a powerful desiccant. When it reacts with water, the reaction is exothermic, meaning it generates significant heat.
The last major group of ions are radical ions, or just radicals. Examples of radicals include superoxide (O2-), which the immune system uses to kill invading microorganisms, and nitric oxide, which the body uses as an important signaling molecule. Like acids and bases, radicals are highly reactive and have a number of applications in chemistry. One unfortunate aspect of radicals is that trace amounts in the body tend to break down tissues over time, contributing to aging.
Salt:
In chemistry, salts are ionic compounds that can result from the neutralization reaction of an acid and a base. Salts are ionic compounds composed of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge). These component ions can be inorganic such as chloride (Cl−), as well as organic such as acetate (CH3COO−) and monatomic ions such as fluoride (F−), as well as polyatomic ions such as sulfate (SO42−).
There are several varieties of salts. Salts that hydrolyze to produce hydroxide ions when dissolved in water are basic salts and salts that hydrolyze to produce hydronium ions in water are acid salts. Neutral salts are those that are neither acid nor basic salts. Zwitterions contain an anionic center and a cationic center in the same molecule but are not considered to be salts. Examples include amino acids, many metabolites, peptides and proteins.
Molten salts and solutions containing dissolved salts (e.g. sodium chloride in water) are called electrolytes, as they are able to conduct electricity. As observed in the cytoplasm of cells, in blood, urine, plant saps and mineral waters, mixtures of many different ions in solution usually do not form defined salts after evaporation of the water. Therefore, their salt content is given for the respective ions.
Different salts can elicit all five basic tastes, e.g., salty (sodium chloride), sweet (lead diacetate, which will cause lead poisoning if ingested), sour (potassium bitartrate), bitter (magnesium sulfate), and umami or savory (monosodium glutamate).
Acid salts is a somewhat obscure term for a class of salts formed by the partial neutralization of diprotic or polyprotic acids. Because the parent acid is only partially neutralized, one or more replaceable protons remain. Typical acid salts have one or more alkali metal ions as well as one or more protons. Well known examples are sodium bicarbonate (NaHCO3), sodium hydrosulfide (NaHS), sodium bisulfate (NaHSO4), monosodium phosphate (NaH2PO4), and disodium phosphate (Na2HPO4). Often acid salts are used as buffers.[1]
For example, the acid salt sodium bisulfate is the main species formed upon the half neutralization of sulfuric acid with sodium hydroxide:
H2SO4 + NaOH → NaHSO4 + H2O
Acid salts compounds can act either as an acid or a base: addition of a suitably strong acid will restore protons, and addition of a suitably strong base will remove protons. The pH of a solution of an acid salt will depend on the relevant equilibrium constants and the amounts of any additional base or acid. A comparison between the Kb and Ka will indicate this: if Kb > Ka, the solution will be basic, whereas if Kb < Ka, the solution will be acidic.
Use in food
Main article: baking powder
Some acid salts are used in baking. They are found in baking powders and are typically divided into low-temperature (or single-acting) and high-temperature (or double-acting) acid salts. Common low-temperature acid salts react at room temperature to produce a leavening effect. They include cream of tartar, calcium phosphate, and citrates. High-temperature acid salts produce a leavening effect during baking and are usually aluminium salts such as calcium aluminium phosphate. Some acid salts may also be found in non-dairy coffee creamers.
An ion is a charged species, an atom or a molecule, that has lost or g
ained one or more electrons. Positively charged cations (e.g. sodium cation Na+) and negatively charged anions (e.g. chloride Cl−) can form a crystalline lattice of neutral salts (e.g. sodium chloride NaCl). Examples of polyatomic ions that do not split up during acid-base reactions are hydroxide (OH−) and phosphate (PO43−).Ions in the gaseous phase are often known as plasma.
An ion is an atom or molecule with more or less electrons than usual, giving it a positive or negative electric charge. Because an ion "wants" to become neutral by acquiring or losing additional electrons, it has interesting chemical features. Ions usually come in the form of solutions. There are three types -- anions, which are negatively charged, cations, which are positively charged, and radicals, or radical ions, which are highly reactive due to having a large amount of free electrons.
An ion solution is typically created when certain molecules, such as salt, are dissolved in water. The interactions between the solute and solvent molecules disassociate weakly-bonded molecules, like salt, into two or more ions. When salt is put into water, it breaks into sodium and chloride ions, both of which are essential to human life. If a person is deprived of salt for too long, they will eventually die. Other life-essential ions (called electrolytes) are potassium (K+), calcium (Ca2+), magnesium (Mg2+), hydrogen phosphate (HPO42−), and hydrogen carbonate (HCO3−).
Other ion solutions besides dissolved salts are acids and bases. For instance, hydrochloric acid is formed when hydrogen chloride is dissolved in water. The hydrogen chloride breaks into two ions, H+ and Cl−. The H+ reacts with water to produce H3O+, hydronium ion, while the chlorine remains as a chloride ion. Because the ionization process is complete, hydrochloric acid is called a strong acid. The strength of acids is measured by how many H+ ions they have -- hydrochloric acid many, so it is very acidic. In fact, hydrochloric acid can dissolve through glass and all metals except iridium, though its corrosion speed is slow.
Another category of ion solutions are bases. Instead of being measured by the concentration of hydrogen ions, a base is measured by its concentration of hydroxide ions (OH-). One example of a base is potassium hydroxide, which is the chemical precursor of most soft and liquid soaps. When dissolved in water, potassium hydroxide produces a strong alkali solution. An alkali is a type of base. Potassium hydroxide has a number of interesting chemical properties -- one of them is its hygroscopic (water-attracting) nature, which makes it a powerful desiccant. When it reacts with water, the reaction is exothermic, meaning it generates significant heat.
The last major group of ions are radical ions, or just radicals. Examples of radicals include superoxide (O2-), which the immune system uses to kill invading microorganisms, and nitric oxide, which the body uses as an important signaling molecule. Like acids and bases, radicals are highly reactive and have a number of applications in chemistry. One unfortunate aspect of radicals is that trace amounts in the body tend to break down tissues over time, contributing to aging.
Salt:
In chemistry, salts are ionic compounds that can result from the neutralization reaction of an acid and a base. Salts are ionic compounds composed of cations (positively charged ions) and anions (negative ions) so that the product is electrically neutral (without a net charge). These component ions can be inorganic such as chloride (Cl−), as well as organic such as acetate (CH3COO−) and monatomic ions such as fluoride (F−), as well as polyatomic ions such as sulfate (SO42−).There are several varieties of salts. Salts that hydrolyze to produce hydroxide ions when dissolved in water are basic salts and salts that hydrolyze to produce hydronium ions in water are acid salts. Neutral salts are those that are neither acid nor basic salts. Zwitterions contain an anionic center and a cationic center in the same molecule but are not considered to be salts. Examples include amino acids, many metabolites, peptides and proteins.
Molten salts and solutions containing dissolved salts (e.g. sodium chloride in water) are called electrolytes, as they are able to conduct electricity. As observed in the cytoplasm of cells, in blood, urine, plant saps and mineral waters, mixtures of many different ions in solution usually do not form defined salts after evaporation of the water. Therefore, their salt content is given for the respective ions.
Different salts can elicit all five basic tastes, e.g., salty (sodium chloride), sweet (lead diacetate, which will cause lead poisoning if ingested), sour (potassium bitartrate), bitter (magnesium sulfate), and umami or savory (monosodium glutamate).
Acid salts is a somewhat obscure term for a class of salts formed by the partial neutralization of diprotic or polyprotic acids. Because the parent acid is only partially neutralized, one or more replaceable protons remain. Typical acid salts have one or more alkali metal ions as well as one or more protons. Well known examples are sodium bicarbonate (NaHCO3), sodium hydrosulfide (NaHS), sodium bisulfate (NaHSO4), monosodium phosphate (NaH2PO4), and disodium phosphate (Na2HPO4). Often acid salts are used as buffers.[1]
For example, the acid salt sodium bisulfate is the main species formed upon the half neutralization of sulfuric acid with sodium hydroxide:
H2SO4 + NaOH → NaHSO4 + H2O
Acid salts compounds can act either as an acid or a base: addition of a suitably strong acid will restore protons, and addition of a suitably strong base will remove protons. The pH of a solution of an acid salt will depend on the relevant equilibrium constants and the amounts of any additional base or acid. A comparison between the Kb and Ka will indicate this: if Kb > Ka, the solution will be basic, whereas if Kb < Ka, the solution will be acidic.
Use in food
Main article: baking powder
Some acid salts are used in baking. They are found in baking powders and are typically divided into low-temperature (or single-acting) and high-temperature (or double-acting) acid salts. Common low-temperature acid salts react at room temperature to produce a leavening effect. They include cream of tartar, calcium phosphate, and citrates. High-temperature acid salts produce a leavening effect during baking and are usually aluminium salts such as calcium aluminium phosphate. Some acid salts may also be found in non-dairy coffee creamers.
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