Chapter 23: Acids, Bases, and Salts
common bases
house cleaning products, antacid, fertilizer `
neutralization
a chemical reaction between an acid and a base that takes place in a water solution
salt formation
a compound formed when the negative ions from an acid combine with the positive ions from a base
salts are composed of
a positive metal ion and an ion with a negative charge, such as Cl-
titration
a solution of known concentration is used to determine the concentration of another solution
acids
a substance that produces hydrogen ions in a water solution. When an acid dissolves in water H+ ions interact with water molecules to form H3O+ ions, hydronium ions.
acid-base reaction
acid+base----> salt+water
ammonia
ammonia is a base that does not contain -OH, in a water solution, dissociation takes place when the ammonia molecule attracts a hydrogen ion from a water molecule, forming an ammonium ion (NH4+) this leaves a hydroxide ion (OH-)
bases
any substance that forms hydroxide ions,OH-, in water solution, any substance that accepts H+ from acids
ions
can conduct an electric current, the more ions a solution contains the more current it can conduct
common acids
citric acid, stomach acid, fertilizer
neutralization + salt formation
half of the ions in the solution react to form water and half form salt
H+
hydrogen
H3O
hydronium
OH-
hydroxide
properties of bases
in a pure, undissolved state, many bases are crystalline solids, feel slippery, bitter taste, corrosive, cause burns, turns litmus paper blue
esters
made from acid and water is formed in the reaction used to prepare them, come from alcohols that are not bases but have a hydroxyl group
strong acid
nearly all the acid molecules dissociate into ions ex: nitric acid, hydrochloric acid, sulfuric acid
weak acid
only a small fraction of the molecules dissolve in water ex: acetic acid and carbonic acid
soaps
organic salts, have a nonpolar organic chain of carbon atoms on one end and either a sodium or potassium salt of a carboxylic,-COOH, group at the other end. the nonpolar,hydrocarbon end interacts with oils and first so that they can be removed readily and the ionic end helps them dissolve in water
neutral
pH of 7, indicates that the concentrations of H+ ions and OH- ions are equal
strong and weak
refers to the ease with which an acid or base dissociates in a solution
uses for esters
soaps, perfumes, flavors, clothing
buffers
solutions containing ions that react with additional acids or bases to minimize their effects on pH ex: buffers help keep your blood close to a nearly constant pH of 7.4
acidic
solutions with a pH lower than 7, the lower the value is, the more acidic
basic
solutions with pH greater than 7, the higher the value is, the more basic
properties of acids
sour taste, can cause painful burns, corrosive, turns litmus paper red
pH
the measure of the concentration of H+ (hydrogen) ions in it, the greater the H+ concentration is, the lower the pH is and the more acidic the solution is
how titration happens
the standard solution (known concentration) is added slowly and carefully to a solution of unknown concentration to which an acid/base indicator has been added. If the solution of unknown concentration is a base, a standard acid solution is used. If the unknown is an acid, a standard base solution is used.
dilute and concentrated
used to indicate the concentration of a solution, which is the amount of acid or base dissolved in a solution
example of neutralization
when HCI is neutralized by NaOH, hydronium ions from the acid combine with hydroxide ions from the base to produce neutral water
dissociation of acids
when an acid dissolves in water, the negative areas of nearby water molecules attract the positive hydrogen in the acid, the acid dissociates or separates into ions and the hydrogen atom combines with a water molecule to form hydronium ions (H3O+)
dissociation of bases
when bases that contain -OH dissolve in water, the negative areas of nearby water molecules attract the positive ion in the base, the base dissociates into a positive and negative ion- a hydroxide ion (OH-), unlike acid dissociation, water molecules do not combine wth the ions formed from the base