acids and bases

Question 1

litmus paper in acids

Answer 1

turns blue litmus paper red

Question 2

litmus paper in bases

Answer 2

turns red litmus paper blue

Question 3

Arrhenius acids

Answer 3

a substance that produces H + ions in aqueous solutions

Question 4

Arrhenius base

Answer 4

a substance that produces OH- ions in aqueous solution

Question 5

limitations of Arrhenius’s theory

Answer 5

1. H+ does not exist in the water we always find H3O+
2. only classifies acids and bases in water
3. explains the basic properties of substances without OH- like NH3

Question 6

bronsted lowry theory

Answer 6

refers to proton donors and proton acceptors

Question 7

bronsted lowry acid

Answer 7

proton donor

Question 8

bronsted lowry base

Answer 8

proton acceptor

Question 9

amphoteric

Answer 9

can act as an acid or as a base

Question 10

what does the strength of an electrolyte depend on?

Answer 10

on the extent of its dissociation into its component ions

Question 11

strong electrolyte

Answer 11

completely dissociates into ions in solution

Question 12

weak electrolyte

Answer 12

partially dissociates into ions in solution

Question 13

what does it mean if the equilibrium lies to the right

Answer 13

acid is strong

Question 14

what does it mean if the equilibrium lies to the left?

Answer 14

the acid is weak

Question 15

what influences the degree to which an acid is strong or weak

Answer 15

the attraction between the anion of the acid and the hydrogen ion

Question 16

what is the conc of water in water

Answer 16

55.5 mol

Question 17

why do we ignore water concentration in the equilibrium constant?

Answer 17

because the concentration of water in water is 55.5 mol and when we add acid, the conc of water barely changes

Question 18

high Ka

Answer 18

the equilibrium is lying on the right: strong acid

Question 19

low Ka

Answer 19

the equilibrium lies to the left: weak acid

Question 20

autoionisation of water

Answer 20

H20 + H20 ⇌ H3O+ +OH-

Question 21

neutral

Answer 21

[H3O+] = [OH-]

Question 22

acidic

Answer 22

[H3O+] > [OH-]

Question 23

basic

Answer 23

[H3O+] < [OH-]

Question 24

ionization constant for water

Answer 24

Kw = [H3O+] [OH-] = 10^-14 mol

Question 25

pH

Answer 25

pH= -log[H3O+]

Question 26

when does a substance behave as an acid

Answer 26

if it is a stronger acid than water: if its Ka is higher than Kw

Question 27

Ka higher than 1

Answer 27

strong acid

Question 28

Ka lower than 10^-14

Answer 28

it will behave as a base

Question 29

equation for strong acids

Answer 29

[H3O+] = Ca (initial)

Question 30

equation for weak acids

Answer 30

H3O+ = square root( Ka x Ca)

Question 31

equation for weak base

Answer 31

OH- = square root( Kb x Cb)

Question 32

lewis acid

Answer 32

electron pair acceptor

Question 33

lewis base

Answer 33

electron pair donor

Question 34

buffer

Answer 34

resists pH change by neutralizing added acid or added base

Question 35

what does a buffer consist of

Answer 35

of a weak acid and a conjugate base in similar concentrations or a weak base and its conjugate acid.

Question 36

what do we need when we want to buffer something

Answer 36

a substance with a pKa close to the pH we want to buffer

Question 37

Henderson Hasselbach Equation

Answer 37

pH = pKa + log [base]/[acid]

Question 38

blood pH

Answer 38

7.35- 7.45

Question 39

example of a buffer in biological fluids

Answer 39

carbonic acid/bicarbonate system: CO2 + H2O ⇌ H2CO3