chap 11 key terms Flashcards
accuracy
Accuracy- The value of a measurement is considered to be accurate if its judged to be close to the true value of the quantity being measured.
acid
Acid- a substance capable of donating a hydrogen ion (proton).
acid-base reaction
Acid-base reaction- A reaction in which one substance, an acid, donates a hydrogen ion (proton) to another substance, a base.
acidic proton
Acidic proton- A proton bonded to an electronegative element (oxygen, nitrogen or fluorine) that’s donated to a base during an acid-base reaction.
acidic solution
Acidic solution- An aqueous solution in which the concentration of hydronium ions (H3O+) is greater than the concentration of hydroxide ions (OH-). At 25OC, pH < 7.
acidity
Acidity- The concentration of H3O+ ions in an aqueous solution. Acidity is measured using the pH scale.
alkali
Alkali- A soluble base or solution of a soluble base.
amphiprotic
Amphiprotic- The ability to act as an acid (proton donor) and also as a base (proton acceptor).
antacids
Antacids- Substances that neutralise stomach acidity. They are often soluble metal hydroxides or carbonates or a mixture of both.
base
Base- A substance capable of accepting a hydrogen ion (proton).
basic solution
Basic solution- An aqueous solution in which [H3O+] < [OH-]. For a basic solution at 25OC, pH > 7.
bronsted-lowry theory
Bronsted-Lowry theory- A theory that defines an acid as a proton (hydrogen ion) donor and a base as a proton acceptor. In the reaction HCl(g) + H2O(l) H3O+(aq) + Cl-(aq), HCl is the proton donor and is classified as an acid. H2O is a proton acceptor and is classified as a base.
calcification
Calcification- The building of a deposit of insoluble calcium salts, mainly calcium carbonate. It occurs in the formation of bone and in the development of shells in marine organisms.
concentrated solution
Concentrated solution- A solution that has a relatively high ratio of solute to solvent.
concentration
Concentration- A measure of how much solute is dissolved in a specified volume of solution.
conjugate acid
Conjugate acid- The conjugate acid of a base contains one more hydrogen ion (proton) than the base, e.g. HCl is the conjugate acid of Cl-.
conjugate acid-base pair
Conjugate acid-base pair- An acid and its conjugate base. The conjugate base contains one less hydrogen ion (proton) than the acid.
conjugate base
Conjugate base- The conjugate base of an acid contains one less hydrogen ion (proton) than the acid, e.g. Cl- is the conjugate base of HCl.
decalcification
Decalcification- The removal or loss of calcium or calcium compounds.
diprotic acid
Diprotic acid- An acid that can ionise in water to form two H3O+ ions.
dissociate
to break up
greenhouse effect
Greenhouse effect- The warming of the earths atmosphere due to the absorption of infrared radiation by gases such as carbon dioxide, water and methane.
hydronium ion
Hydronium ion- The H3O+(aq) ion.
hydroxide ion
Hydroxide ion- The OH-(aq) ion.
indicator
Indicator- A substance that is different colours in its acid and base forms.
ionic equation
Ionic equation- An equation for a reaction that only includes the ions that are involves in the reaction.
ionisation
Ionisation- (i) the removal of one or more electrons from an atom or ion; (ii) the reaction of a molecular substance with a solvent to form ions in solution.
ionisation constant of water
Ionisation constant of water- The equilibrium constant KW, where KW = [H3O+][OH-]. At 25OC, KW = 1.00 x 10-14 M2.
ionisation reaction
Ionisation reaction- The reaction of an acid or base with water.
ionise
Ionise- The reaction of a molecular substance with a solvent to form ions in solution. When some polar molecules dissolve in water they ionise to form a hydronium ion, e.g. HCl(g) + H2O(l) H3O+(aq) + Cl-(aq).
limewater test
Limewater test- A test for carbon dioxide gas. The presence of carbon dioxide is detected by bubbling the gas through a calcium hydroxide solution (Ca(OH)2(aq)). The limewater reacts with the carbon dioxide and turns milky.
monoprotic acid
Monoprotic acid- An acid molecule that generates only one hydronium ion when ionised in water.
natural indicator
Natural indicator- An indicator that can be found in plants, such as red cabbage, turmeric, cherries, beetroot and grape juice. Like commercial indicators, natural indicators can be used to determine whether a substance is acidic or basic.
natural solution
Neutral solution- A solution in which the concentrations of H3O+ ions equals the concentration of OH- ions; is neither acidic nor basic. At 25OC, a neutral solution has a pH of 7.
neutralization reaction
Neutralization reaction- An acid reacts with a base in stoichiometric proportions to form a salt plus water.
ocean acidity
Ocean acidity- The reduction in the pH of the ocean caused mainly by absorption of atmospheric carbon dioxide.
pH
pH- A measure of acidity and the concentration of hydronium ions, in solution. Acidic solutions have a pH value less than 7 at 25OC, and bases have a pH value greater than 7 (at 25OC). Mathematically, pH is defined as pH = -log10[H3O+).
polyprotic acid
polyprotic acid- An acid molecule that generates more than one hydronium ion when ionised in water.
precision
precision- A measure of the repeatability or reproducibility of scientific measurements and refers to how close two or more measurements are to each other.
salt
salt- A substance formed from a metal or ammonium cation and an anion. Salts are the products of reactions between acids and bases, metal oxides, carbonates and reactive metals.
saturated solution
saturated solution- A solution that cant dissolve any more solute at the given temp.
self-ionisation
self-ionisation- An ionisation reaction of pure water I which water behaves as both an acid and a base.
spectator ion
spectator ion- An ion that remains in solution and is unchanged in the course of a reaction. Spectator ions aren’t included in ionic equations.
strong acid
strong acid- An acid that readily donates a hydrogen ion (proton) to a base.
strong base
strong base- A base that readily accepts a hydrogen ion (proton) from an acid.
triprotic acid
triprotic acid- An acid molecule that generates 3 hydronium ions when ionised in water.
weak-acid
weak acid- an acid that is partly ionised in water.
weak base
weak base- A base that accepts hydrogen ions (protons) from acids to a limited extent.