U2- Acids + Bases

Question 1

Bronsted-Lowry acid

Answer 1

a species that donates a proton, H+, during an acid-base reaction

Question 2

general properties of acids

Answer 2

change colour of some indicators (exception eg is phenolphthalein indicator)
tend to be corrosive
sour
react w bases
pH<7
solutions can conduct electric current (bc covalent molecules can ionise and ions are free to move and carry e charge)

Question 3

Bronsted-Lowry base

Answer 3

a species that accepts a proton, H+, during an acid-base reaction

Question 4

alkali

Answer 4

soluble base that dissociates (splits up) hydroxide ions

Question 5

general properties of bases

Answer 5

red litmus -> blue
slippery
bitter
caustic (react w living tissue)
react w acids
pH>7 (alkali only)
solutions can conduct electric current (alkali only)

Question 6

ionisation

Answer 6

process by which a chemical species gains or loses an electric charge

Question 7

dissociation

Answer 7

process by which a molecule separates into smaller particles

Question 8

acid + alkali

Answer 8

[BAWS] salt (aq) + water (l)

Question 9

acid + metal

Answer 9

[MASH] salt (aq) + hydrogen gas (g)

Question 10

acid + carbonate

Answer 10

[CAWCS] salt (aq) + carbon dioxide (g) + water (l)

Question 11

conjugate acid-base pairs: NH3 (aq) + H2O (l)

Answer 11

NH3 (aq) + H2O (l) –> NH4+(aq) + OH-(aq)

base. acid. conj acid. conj base.

Question 12

amphiprotic substances

Answer 12

can either donate or accept a proton, H+

eg H2O, HSO4-

Question 13

monoprotic, diprotic, triprotic and polyprotic

Answer 13

species that donates one/two/three/multiple protons, H+, during ionisation

Question 14

strength of acid and bases

Answer 14

how readily an acid or base donates or accepts a proton, H+

Question 15

strong acids + egs

Answer 15

undergo almost complete ionisation when added to water. Almost all acid molecules in solution will donate proton to form aqueous H+ ions
good conductors
eg sulfuric acid
hydrochloric acid
nitric acid

Question 16

weak acids + eg

Answer 16

does not readily donate a proton, H+, in a solution. More reactant acid molecules present I'm solution that product of H+ ions hence <-->
poor conductors
eg ammonium
ethanoic acid
carbonic acid

Question 17

strong bases

Answer 17

readily accepts a proton, H+ and dissociates to form OH- ions and a basic solution in an acid-base reaction
eg O2-
OH-
HPO4 2-
H-
S2-

Question 18

weak bases + eg

Answer 18

doesn’t readily accept H+ ions. More reactant base molecules present in solution than product of OH- ions hence <–>
eg ammonia
sulphate
ethanoate

Question 19

strength vs concentration

Answer 19

strength of an acid/base relates to what proportion of its molecules will donate/accept a proton, H+
w/a
acid/base concentration depends on how many of those acid/base molecules were in the solution to begin with

Question 20

pH and pH scale

Answer 20

measure of the concentration of H3O+ ions in solution
values of pH arranged on a logarithmic scale

[OH-][H3O+] = 10^-14 M^2

Question 21

alkali

Answer 21

a soluble base

Question 22

pH formulas

Answer 22

(dilute a solution by factor of 10 to increase/decrease pH by 1)
pH = -log [H3O+]
pH = 14 + log [OH-]

Question 23

concentration from pH formulas

Answer 23

[H3O+] = 10 ^-pH
[OH-] = 10 ^pH-14
or
C1V1 = C2V2

Question 24

ionic product of water

Answer 24

Kw = [H3O+] x [OH-] = 1 x 10^-14

constant value tf as [H3O+] increases, [OH-] must decrease to maintain constant and vice versa

Question 25

acid dissociation constant, Ka

Answer 25

used to distinguish strong acids from weak acids (higher=stronger)
Ka = [H3O+][A-]
—————-
[HA]

Question 26

hydrolysis

Answer 26

chemical reaction where water is used to break the bonds of a substance

Question 27

acid-base reactions

Answer 27

chemical reaction where a proton, H+, is transferred between two chemical species

Question 28

ionic equation

Answer 28

simplified equations not including spectator ions

Question 29

spectator ions

Answer 29

aqueous ions which do not react and remain dissolved in a solution throughout a reaction

Question 30

conjugate acid/base

Answer 30

chemical species formed from a base/acid that has accepted/donated a proton, H+

Question 31

concentration

Answer 31

amount of chemical substance in a unit of volume

Question 32

concentrated vs dilute solution

Answer 32

relatively high vs relatively low amount of solute compared to the volume of solution