acids and bases

Question 1

bronsted acid

Answer 1

proton donor

Question 2

strong acid

Answer 2

acid which ionises almost completely in an aqueous soln
eqm very far right
large Ka
HNO3, HCL,H2SO4

Question 3

bronsted base

Answer 3

proton acceptor

Question 4

weak acid

Answer 4

acid that only ionises partially in an aqueous soln
eqm lies far left
small ka

Question 5

ionisation

Answer 5

reaction of a molecular substance with water to produce ions

Question 6

dissociation

Answer 6

splitting of an ionic compound into its ions

Question 7

polyprotic acids

Answer 7

able to donate more than one proton

Question 8

dilute acid

Answer 8

small no. of moles in acid

Question 9

strong base

Answer 9

base that dissociates almost completely in an aqueous soln
high Kb value
group 1 hydroxides

Question 10

weak base

Answer 10

base that ionises partially in an aqueous soln
low Kb value

Question 11

test for strong or weak base

Answer 11

conductivity

Question 12

test for strong or weak base

Answer 12

conductivity

Question 13

strength of an acid/base

Answer 13

independent of concentration of soln

Question 14

concentrated acid/base

Answer 14

contains very large amount of acid/base than water in soln
has relatively more dissolved solute than a dilute soln

Question 15

conjugate base pairs

Answer 15

1 product and 1 reactant, 1 H+ difference
stronger an acid/base- weaker its conjugate

Question 16

conjugate base

Answer 16

substance formed when acid loses 1 proton

Question 17

conjugate acid

Answer 17

substance formed when base gains one 1 proton

Question 18

amphoterrpic/amphiprotic substance

Answer 18

substance that can act as either an acid or a base
H2O (water) , HCO3- (hydrocarbonate), HSO3- (hydrogen sulphate)

Question 19

autoprolysis

Answer 19

auto-ionisation of water
self ionises to extremely limited extent
concentration of ions extremely low- eqm far left

Question 20

Kw

Answer 20

1x10^-14 @25 degrees celcius

Question 21

pH scale

Answer 21

measure of hydronium concentration in soln @25 degrees celcius

= -log[H3O+]
high number-low pH
small number-high pH

Question 22

hydrolysis

Answer 22

reaction of an anion( from a salt) with water
occurs when salt of weak acid/base/both is dissolved in water causing water itself to decompose in rxn w ions of the salt
salt breaks down into pos + neg ions
water undergoes autoprolysis
conjugate ions of strong acids/bases and group 1 metals do NOT undergo hydrolysis

Question 23

neutralisation

Answer 23

a chemical reaction in which an acid + a base react so that neither is in excess
forms salt and water
equivalence point should be the same as end point if done correctly.

Question 24

standard solution

Answer 24

solution of known concentration

Question 25

standard solution

Answer 25

solution of known concentration

Question 26

acid-base titrations

Answer 26

acidic soln of known concentration added from a burette to a conical flask containing basic soln of unknwon concentration or vice versa, until end point is reached (indicator changes colour)
unknown concentration is calculated from readings from burrette
CHECK - titration point and equivalence point must be same

Question 27

salt

Answer 27

substance in which the hydrogen of an acid has been replaced by a cation

Question 28

salt

Answer 28

substance in which the hydrogen of an acid has been replaced by a cation

Question 29

smaller Kb

Answer 29

weaker base

Question 30

larger kb

Answer 30

stronger base

Question 31

conjugate base

Answer 31

substance formed when acid loses 1 proton

Question 32

conjugate base

Answer 32

substance formed when acid loses 1 proton

Question 33

conjugate acid

Answer 33

substance formed when base gains 1 proton

Question 34

neutral salt

Answer 34

made of strong acid + strong base
complete dissociation + ionisation
no hydrolysis will occur
no disruption to equal concentration of H3O+ and OH- ions in soln
salt has pH of 7

Question 35

acidic salt

Answer 35

strong acid + weak base
acid ions will not undergo hydrolysis (conjugate of strong acid)
base undergoes hydrolysis forms product of weak base which will not dissociate complete
the formation of the weak base removes OH- ions from water
disruption to concentration of OH- and H3O+ ions in soln
water equilibrium shifts right to replace (OH-)
therefore the concentration of H3O+ ions increases
hence the salt is acidic , and the pH is less than 7

Question 36

basic salt

Answer 36

weak acid + strong base
base does not undergo hydrolysis (dissociates completely)
therefore weak acid undergoes hydrolysis
product formed is a weak acid (won’t ionise completely)
formation of weak acid removes H+ ions , thus leading to a disruption in the concentration of H3O+ and OH- in soln.
The water equilibrium shifts right to replace H3O+ ions resulting in an increase in the concentration of [OH- ions]
therefore salt is basic , pH is larger than 7

Question 37

acid-base titrations

Answer 37

titration - volumetric analysis
acidic solution of non-concentration ( standard solution) is added from a burette to a conical flask (containing basic solution of undone concentration measured in pipette in fixed volume) vice versa until endpoint is reached (indicator changes colour)
unknown [ ] is calculated from readings from burette
CHECK: titration end point should = equivalence point

Question 38

equivalence point vs end point

Answer 38

equivalence- point in a titration where neither reactant is in excess
end point / point where indicator changes colour