Chemicals {acid, chemistry} can accept electron pairs or donate protons. Acids donate protons {Brönsted acid}, accept electron pairs {Lewis acid}, or add hydrogen ions to water when they dissolve. Acids {polyprotic acid} can donate more than one proton.
properties
Acids taste sour, are colorless, and are corrosive.
production
Dissolving non-metallic oxide in water makes acid.
factors
For diatomic acids, acidity increases with negative-ion atomic weight. Acidity increases with increasing number of no-hydrogen oxygens around central atom.
acids
Common acids are nitric acid, sulfuric acid, hydrochloric acid, hydrofluoric acid, carbonic acid, phosphoric acid, formic acid, acetic acid, and other carboxylic acids.
Solution acidity {acidity}| is negative logarithm of hydrogen-ion concentration: pH = -log(H+). pH can range from 0 to 14. Pure water has dissociation constant K = 10^-7, so pK is 7, and pH is 7. Pure water is neither acid nor base. 1 M hydrochloric acid has pH 0. Lemon juice has pH 2. Soda water has pH 4. Coffee has pH 5. Urine and rain have pH 6. Water has pH 7. Bicarbonate of soda has pH 8. Milk of magnesia has pH 10. Cleaning ammonia has pH 11. 1 M sodium hydroxide has pH 14.
Chemicals {amphiprotic} can either donate or accept proton.
Molecules {amphoteric} can have both acidic and basic groups.
Chemicals {base, chemistry}| can donate electron pairs or accept protons. Bases accept protons {Brönsted base}, donate electron pairs {Lewis base}, or donate hydroxide ions to water when they dissolve. Bases taste bitter, are colorless, are slippery, and are caustic. Dissolving metal oxide in water makes base. Bases include sodium hydroxide, potassium hydroxide, ammonium hydroxide, magnesium hydroxide, calcium hydroxide, and aluminum hydroxide.
To keep solution pH constant {buffer}|, add weak acid or base and soluble salt with same anion. Weak-acid anion acts as weak base. Weak-base anion acts as weak acid. Adding acid or base to solution causes weak base or acid to neutralize added acid or base. However, adding too much acid or base can overwhelm weak acid or base. Weak-acid or base concentration to soluble-salt concentration ratio, and anion dissociation constant, determine buffer pH. Citrate buffer has pH near 5. Bicarbonate buffer has pH near 6. Phosphate buffer has pH near 7. Tris buffer has pH from 4 to 8.
Bases {caustic, base}| can react with organic matter.
After base accepts proton, it becomes weak acid {conjugate acid}.
After acid donates proton, it becomes weak base {conjugate base}.
Acids {corrosive}| can react with metals and inorganic materials.
Solutes dissolve in solvent {dissociation, chemistry}|. Buffer, weak-acid, or weak-base solution has low dissociation. Dissociation constant equals hydrogen ion concentration times anion concentration divided by acid concentration. Water dissociation constant = 10^-14, so hydrogen ion = 10^-7 M. Water ionization is more if temperature is more.
Weak acids have hydrogen ion and anion {hydrolysis}|. Salts with anion react with water to associate some hydrogen ion and form weak bases. Weak bases have hydroxide ion and cation. Salts with cation react with water to associate some hydroxide ion and form weak acids.
Hydrogen ions in water bind to water molecules electrically to make positively charged ion {hydronium ion}: H+ + H2O -> H3O+ [2 and 3 are subscripts, and + is superscript].
Weak acids or bases {indicator, acidity}| with conjugated double bonds can change electronic structure and color at different pH. At pH 1, malachite green changes from yellow to green. At pH 2, thymol blue changes from red to yellow. At pH 4, bromphenol blue changes from yellow to blue. At pH 4, methyl orange changes from red to yellow. At pH 4.5, bromcresol green changes from yellow to blue. At pH 5, methyl red changes from red to yellow. At pH 7, bromthymol blue changes from yellow to purple. At pH 7.4, phenol red changes from yellow to red. At pH 9, phenolphthalein changes from clear to red. At pH 9, thymol blue changes from yellow to blue. At pH 10, thymolphthalein changes from clear to blue. At pH 11, alizarin yellow R changes from yellow to red.
Acid and base reactions make water, metal anions, and non-metal cations {acid-base reaction, inorganic} {neutralization}|. Neutralization reactions involve proton transfer. Acid and base neutralize each other, because metal anions and non-metal cations are not very acidic or basic.
As concentration decreases, ionized-acid percentage increases {Ostwald's dilution law} {Ostwald dilution law}.
In acid-base reactions, anion and cation can attract electrically to form compounds {salt}|.
5-Chemistry-Inorganic-Acid-Base
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Date Modified: 2022.0225