8 - Acids and Bases

Question 1

Arrhenius theory

Answer 1

in an aqueous solution, an acid is a substance that produces hydrogen ions and a base is a substance that produces hydroxide ions

Question 2

Bronsted-Lowry theory

Answer 2

an acid is a hydrogen ion (proton) donor and a base is a hydrogen ion (proton) acceptor, accounts for bases without OH-

Question 3

conjugate acid

Answer 3

the substance that forms when a base, according to the Bronsted Lowry theory, accpets a hydrogen ion (proton)

Question 4

conjugate base

Answer 4

the substnace that forms when an acid loses a hydrogen ion (proton)

Question 5

conjugate acid-base pair

Answer 5

two substances related to each other by the donating an accepting of a single hydrogen ion

Question 6

amphiprotic (amphoteric)

Answer 6

able to donate or accept a hydrogen ion (proton) and thus acr as both a Bronsted-Lowry acid and a Bronsted-Lowry base

Question 7

acid ionization contant (Ka)

Answer 7

equilibrium contant for the ionization of an acid; also called the acid of dissociation contant

Question 8

strong acid

Answer 8

an acid that ionizes almost 100 percent in water, producing hydrogen ions

Question 9

weak acid

Answer 9

an acid that only partly ionizes

Question 10

organic acid

Answer 10

an acid (expcept carbonic acid) containing carbon, oxygen, and hydrogen atoms, also called carboxylic acid

Question 11

strong base

Answer 11

a base that dissociated completley in water, producing hydroxide ions

Question 12

weak base

Answer 12

a base that only partially reacts with water to produce hydroxide ions

Question 13

base ionization constant

Answer 13

the equilibrium constant for the ionization of a base; also called the base dissociation constant

Question 14

organic base

Answer 14

an organic compound that increases the concentration of hydroxide ions in aqueous solution

Question 15

autoionization of water

Answer 15

the transfer of a hydrogen ion from one water molecule to another

Question 16

ion-product constant for water

Answer 16

the equilibrium consrtant for the autoionization of water

Question 17

pH meter

Answer 17

a devide that measures the acidity or alkalinity of a solution electronically and displays the result as a pH value

Question 18

monoprotic acid

Answer 18

an acid that possess only one ionizable (acidic) hydrogen atom

Question 19

polyprotic acid

Answer 19

an acid that possesses more than one ionizable (acidic) hydrogen atom

Question 20

sample

Answer 20

The solution being analyzed in a titration, which is placed in a receiving
flask (Erlenmeyer flask). The volume is known, but the concentration
is usually unknown.

Question 21

titrant

Answer 21

The solution in the burette during the titration. Concentration of the
titrant is known, and the titrant is added to the sample. The volume of
the titrant needed to neutralize the sample is recorded and used to
calculate the concentration of the sample. If the sample is a base, the
titrant used is an acid, and vice versa.

Question 22

standard solution

Answer 22

A solution whose concentration is accurately and precisely known. Made
by dissolving a primary standard in distilled water.

Question 23

primary standard

Answer 23

A highly pure and stable chemical used to determine the precise
concentration of acids or bases (used to test the accurate concentration
of the titrant). Common primary standards include sodium carbonate,
Na2CO3(s) and potassium hydrogen phthalate, KHC8H4O4(s).

Question 24

Equivalence Point

Answer 24

The point in a titration when neutralization is complete. At this
point, all the reactant in the sample is used up. (na = nb)
In problems, this is the empirically determined point.

Question 25

Endpoint

Answer 25

The point in a titration at which a sharp change in a measurable and characteristic property occurs, usually a colour change.

Question 26

Indicator

Answer 26

A solution of a weak acid or base that changes colour at a certain pH, “indicating” when the equivalence point is reached and titration is complete. Ex) Phenolphthalein for bases, and Methyl Orange for acids

Question 27

pH curve

Answer 27

A graph of pH plotted against volume of titrant added in an acid-base titration. The centre of the vertical region of the pH curve indicates the equivalence point. Also known as a titration curve.