Chapter 8 - Acid Base Equilibrium

Question 1

define Arrhenius theory

Answer 1

a theory stating that, in an aqueous solution, an acid is a substance that produces hydrogen ions (H+) and a base is a substance that produces hydroxide ions(OH-)

Question 2

what is a hydrogen ion

Answer 2

a hydrogen atom without an electron, a proton

Question 3

why was the Arrhenius theory limited?

Answer 3

it allows for only one kind of base (compounds containing hydroxide ion) and it assumes all acid-base reactions occur in aqueous solutions

Question 4

define brønsted-Lowry theory

Answer 4

a theory stating that an acid is a hydrogen ion/proton donor and a base is a hydrogen ion/proton acceptor

Question 5

what does the brønsted-lowry theory apply to?

Answer 5

all of the Arrhenius acids and bases and some others not categorised as acids and bases under the Arrhenius theory

Question 6

what is an example of a base not categorized as one under the Arrhenius theory definition

Answer 6

NH3, does not contain hydroxide ions, but is a base

Question 7

how is an acid usually produced?

Answer 7

dissolving the compound in water

Question 8

what ions does the Arrhenius theory predict will be produced when an acid is dissolved in water?

Answer 8

hydrogen ions

Question 9

what does experimental evidence disprove about Arrhenius’s theory of hydrogen ions being produced?

Answer 9

hydrogen ions are not stable on their own, they react with the water molecule to form a hydronium ion

Question 10

define a hydronium ion

Answer 10

a water molecule that has accepted a hydrogen ion (H30+)

Question 11

what atom in the water molecule pulls a hydrogen ion away from the molecule and why?

Answer 11

oxygen because it has two lone electron pairs, one of the pairs forms a coordinate covalent bond with the donated hydrogen ion

Question 12

what kind of equilibrium is it when explaining the brønsted-lowry theory and what kind of reaction is it?

Answer 12

a reversible reaction resulting in a dynamic equilibrium

Question 13

what is water in an acidic solution?

Answer 13

a proton acceptor, a base

Question 14

what is water in basic solutions?

Answer 14

a proton donator, an acid

Question 15

what is responsible for the acidic properties of an acidic solution

Answer 15

dissolved hydronium ions

Question 16

what is responsible for the basic properties of a basic solution

Answer 16

hydroxide ions

Question 17

what happens because an acid-base reaction is reversible

Answer 17

a hydrogen ion (proton) transfer may occur in the forward and reverse reaction

Question 18

general equation for the equilibrium reaction of an acid with water to form an acidic solution

Answer 18

HA (aq) + H20 (l) ⟶ A-(aq) + H30+ (aq)

Question 19

define conjugate acid

Answer 19

the substance that forms when a base, according to brønsted-lowry theory, accepts a hydrogen ion (proton)

Question 20

define conjugate base

Answer 20

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

Question 21

what does the hydronium ion act as in an acidic solution?

Answer 21

conjugate acid

Question 22

general equation for the equilibrium reaction of a base with water to form a basic solution

Answer 22

B (aq) + H20 (l) ⟶ HB+ (aq) + OH- (aq)

Question 23

what doe the hydroxide ion act as in a basic solution

Answer 23

conjugate base

Question 24

define conjugate-base pair

Answer 24

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

Question 25

what states can acid-base reactions occur in brønsted-lowry theory?

Answer 25

non-aqueous states and aqueous states

Question 26

give an example of an acid base reaction in a non aqueous state

Answer 26

HCl (g) + NH3 (g) ⟶ NH4Cl (s) (or NH4+ (s) + Cl- (s))

Question 27

what is another term for amphiprotic?

Answer 27

amphoteric

Question 28

define amphiprotic

Answer 28

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

Question 29

2 amphiprotic substances

Answer 29

water and hydrogen carbonate ion (HCO3- (aq)

Question 30

2 reaction where water and hydrogen carbonate ions are amphiprotic, including whether they act as bases or acids

Answer 30

HCO3- (aq) (base) + H20 (l) (acid) ⟶ H2CO3+ (aq) (conjugate acid) + OH-(aq) (conjugate base) and HCO3- (aq) (acid) + H20- (l) (base) ⟶ CO3^2- (aq) (conjugate base) + H30+ (aq) (conjugate acid)