Oceans

Question 1

most ionic substances only dissolve in….

Answer 1

polar solvents

Question 2

most covalent substances only dissolve in….

Answer 2

non-polar solvents

Question 3

ionic solids dissolve in…
to make….

Answer 3

water
aqueous solutions

Question 4

standard lattice enthalpy is….

Answer 4

the enthalpy change when 1 mol of an ionic lattice is formed from its gaseous ions under standard conditions

Question 5

lattice enthalpy is always….
because….

Answer 5

negative
bonds are being broken and energy is being released

Question 6

the more negative the lattice enthalpy….

Answer 6

the stronger the bonding

Question 7

enthalpy change of hydration ions is…

Answer 7

the enthalpy change when 1 mol of aqueous ions is formed from gaseous ions

Question 8

the enthalpy change of solution is….

Answer 8

the enthalpy change when 1 mol of an ionic substance dissolves enough to form an indefinitely dilute solution

Question 9

you can use a _______ _____ or _____ _____ _____ to find the enthalpy change of solution

Answer 9

enthalpy cycle
enthalpy level diagram

Question 10

charge density of an ion =

Answer 10

charge / radius

Question 11

ions with higher charge density have more exothermic lattice enthalpy, why?

Answer 11

the ions are better at attracting each other so ionic bonds are stronger. meaning more energy is released when bonds are made

Question 12

ions with higher charge density have more exothermic hydration enthalpy, why?

Answer 12

ions are better at attracting water molecules so the intermolecular bonds are stronger. meaning more energy is released when bonds are made

Question 13

entropy, S, is…

Answer 13

a measure of the number of ways that particles can be arranged and the number of ways the energy can be shared out between particles

Question 14

how does physical state affect entropy?

Answer 14

solids - hardly any disorder
liquids - some disorder
gases - most disordered

Question 15

which physical state has the highest entropy?

Answer 15

gas

Question 16

which physical state has the lowest entropy?

Answer 16

solid

Question 17

how does no. of moles affect entropy?

Answer 17

when no. of moles increases, entropy increases

Question 18

ΔtotS =

Answer 18

ΔsysS + ΔsurrS

Question 19

ΔsysS =

Answer 19

S products - S reactants

Question 20

ΔsurrS =

Answer 20

-enthalpy change / T (k)

Question 21

a feasible reaction is….

Answer 21

one that once started will carry on to completion without zero energy being supplied to it

Question 22

for a reaction to be feasible the total entropy change must be…

Answer 22

positive or zero

Question 23

the equation for finding the temperature for a feasible reaction to occur is…

Answer 23

T = ΔH / ΔsysS

Question 24

Ksp is….

Answer 24

the solubility product

Question 25

when a sparingly soluble solid is dissolved in water to give a saturated solution...

Answer 25

an equilibrium is established

Question 26

for the reaction AaBb (s) --> aA^b+ (aq) + bB^a- (aq) write the expression for Ksp

Answer 26

(A^b+(aq))^a + (B^a-(aq))^b

Question 27

for the reaction AB (s) ---> A+ (aq) + B- (aq) write the equation for Ksp

Answer 27

Ksp = (solubility of AB)^2

Question 28

a neutral solution is one where...

Answer 28

H+ conc = OH- conc

Question 29

pH =

Answer 29

-log10 [H+]

Question 30

strong acids are..

Answer 30

monoprotic

Question 31

monoprotic means.....

Answer 31

each mole of acid produces one mole of hydrogen ions

Question 32

[H+] =

Answer 32

10 ^-pH

Question 33

water can act as...

Answer 33

a base and an acid

Question 34

Kw is... and is only used for finding the...

Answer 34

the ionic product of water pH of strong acids

Question 35

Kw =

Answer 35

[H+] [OH-]

Question 36

Ka is.. and is only used for...

Answer 36

acid dissociation constant weak acids

Question 37

Ka =

Answer 37

[H+]^2 / [HA]

Question 38

pKa =

Answer 38

-log10 Ka

Question 39

a buffer is..

Answer 39

a solution that resists changes in pH when a small amount of acid or base are added or it's diluted

Question 40

acidic buffers are made by..

Answer 40

mixing a weak acid with one of its salts

Question 41

in acidic buffers the weak acid... and the salt..

Answer 41

slightly dissociates completely dissociates

Question 42

if you increase the conc of acid in the buffer

Answer 42

the [H+] conc increases shifting equilibrium to the LHS and pH doesn't change

Question 43

if you increases the conc of the base in the buffer

Answer 43

the [OH-] conc increases shifting eqm to the RHS and pH doesnt change

Question 44

the types of radiation that reaches the Earth's surface are

Answer 44

visible light and UV

Question 45

the type of radiation that the Earth emits is

Answer 45

infrared radiation (heat)

Question 46

the 'IR' window is...

Answer 46

the range of IR frequencies that are not absorbed by atmospheric gases so escapes into space

Question 47

the main greenhouse gases are...

Answer 47

water vapour methane CO2

Question 48

greenhouse gases absorb ________ to make bonds in the molecule _____ more. this extra vibrational energy is _________ on to other molecules in the air by ________ , giving the other molecules more kinetic energy so raising the overall ________

Answer 48

IR radiation vibrate passed collisions temperature

Question 49

a bronsted lowry acid is a....

Answer 49

proton donator

Question 50

a weak acid is...

Answer 50

one that partially dissociates

Question 51

For the ion H2PO4- state the conjugate base

Answer 51

HPO4^2-

Question 52

For the ion H2PO4- state the conjugate acid

Answer 52

H3PO4^-

Question 53

what factors determine the pH of a buffer solution?

Answer 53

- Ka - temperature

Question 54

what is meant by the term conjugate acid-base pairs?

Answer 54

two species differing in H+

Question 55

in water strong acids..

Answer 55

dissociate completely

Question 56

in water strong bases...

Answer 56

ionise completely

Question 57

a Bronsted Lowry base is a...

Answer 57

proton acceptor

Question 58

in water weak acids....

Answer 58

only dissociate slightly

Question 59

what is transferred when acids and bases react?

Answer 59

protons

Question 60

for strong monoprotic acids [H+] =

Answer 60

[acid]

Question 61

if given the pH of a solution you can calculate the [H+]

Answer 61

10^-pH

Question 62

what is the pH of a strong base at 298k given by?

Answer 62

pH = 14 + log[OH-]