Module 5

Question 1

Order w.r.t [A] = 0
Change in [A] = X2

Answer 1

Rate = [X2]^0
So rate stays constant

Question 2

Order w.r.t [A] = 0
Change in [A] = X3

Answer 2

Rate = [X3]^0 = X1
Rate stays constant

Question 3

Order w.r.t [A] = 1
Change in [A] = X2

Answer 3

Rate = [X2]^1 = 2
Rate doubles

Question 4

Order w.r.t [A] = 1
Change in [A] = X3

Answer 4

Rate = [X3]^1 = X3
Rate triples

Question 5

Order w.r.t [A] = 2
Change in [A] = X2

Answer 5

Rate = [X2]^2 = 4
Rate quadruples

Question 6

Order w.r.t [A] = 2
Change in [A] = X2

Answer 6

Rate = [X3]^2 = 9
Rate X9

Question 7

Overall order : 1
Rate equation?
Units of K?

Answer 7

Rate = k [A]
S^-1

Question 8

Overall order : 2
Rate equation?
Units of K?

Answer 8

rate = k [A]^2
dm^3mol^-1s^-1

Question 9

Overall order : 3
Rate equation?
Units of K?

Answer 9

rate = k [A]^2 [B]
dm^6mol^-2s^-1

Question 10

Overall order : 4
Rate equation?
Units of K?

Answer 10

rate = k[A]^2 [B]^2
dm^9mol^-3s^-1

Question 11

Half-life of reactant, t1/2

Answer 11

Time for the concentration of the reactant to reduce by half

Question 12

Ea=
A=
R=

Answer 12

activation energy
pre-exponential factor
gas constant (on data sheet)

Question 13

Enthalpy change of atomization Delta at H theta

Answer 13

The enthalpy change, when one mole of gaseous atoms is formed from its elements under standard conditions

Question 14

First electron affinity Delta EA1 H theta

Answer 14

The enthalpy change, when one electron is added to each atom in one mole of gaseous atoms to form one mole of gaseous 1- ions

Question 15

Second electron affinity Delta EA2 H theta

Answer 15

The enthalpy change, when one electron is added to each ion in one mole of gaseous 1- ions, to form one mole of gaseous 2- ions

Question 16

Entropy, S

Answer 16

The measure of the dispersal of energy in a system. The entropy is greater when the system is more disordered. System becomes energetically more stable when it becomes more disordered.

Question 17

Standard entropy change of reaction, Delta S theta

Answer 17

The entropy change that accompanies a reaction in the molar quantities to expressed in a chemical equation under standard conditions, all reactants and products being in their standard states

Delta S theta (entropy) = sum of entropy of products - sum of entropy of reactants
(See A2 paper 1 definition list for module 5)

Question 18

Rate - determining step

Answer 18

The slowest step of reaction mechanism of a multistate reaction

Question 19

Mole fraction x(A)

Answer 19

Number of moles of A / total number of moles in a gas mixture

Question 20

Partial pressure p(A)

Answer 20

Mole fraction of A x total pressure P

Question 21

Bronsted-Lowry acid

Answer 21

A proton (H+) donor

Question 22

Bronsted-Lowry base

Answer 22

A proton (H+) acceptor

Question 23

Strong acid

Answer 23

Completely dissociates into its ions in solution to donate a proton

Question 24

Weak acid

Answer 24

Partially dissociates in its ions in solution to donate a proton

Question 25

Salt

Answer 25

A compound produced when a H+ ion from an acid is replaced by a metal ion or another positive ion, such as the ammonium ion NH4+

Question 26

Conjugate acid - base pairs

Answer 26

A pair of two species that transform into each other by the gain or loss of a proton (H+)

Question 27

pH=

Answer 27

-log[H+]

Question 28

H+=

Answer 28

10^-pH

Question 29

pKa=

Answer 29

-log[Ka]

Question 30

Ka=

Answer 30

10^-pKa

Question 31

Kw=

Answer 31

[H+][OH-]

Question 32

Buffer solution

Answer 32

A mixture that minimizes pH change on addition of small amount of acid or base

Question 33

Lattice enthalpy Delta LE H

Answer 33

Enthalpy change, when one mole of an ionic compound is formed from its gaseous ions

Question 34

Standard enthalpy change of solution Delta sol H theta

Answer 34

Enthalpy change that takes place with one mole of compound (solute) is completely completely dissolved in water under standard conditions

Question 35

Standard enthalpy change of hydration Delta hyd H theta

Answer 35

The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water filming one mole of aqueous ions under standard conditions

Question 36

Gibbs Equation

Answer 36

*G = H -TS
*=delta
If G > 0, reaction is not feasible
If G < 0 reaction is feasible
If G = 0 system is in equilibrium

Question 37

Standard electrode potential, E theta

Answer 37

Of a half cell; is the e.m.f of a half cell compared with a standard hydrogen half cell measured at 298K or -25° C with solution concentrations of 1moldm^-3 and a gas pressure of 100 kPa (1atm)

Species undergoing reduction must have the more positive E theta value

Question 38

Transition element

Answer 38

A D-Block element that forms an ion with an incomplete d-sub shell

Question 39

Complex ion

Answer 39

A transition metal ion bonded to one or more ligands by coordinate bonds

Question 40

Ligand

Answer 40

A molecule ion that can donate a pair of electrons to the transition metal ion to form a coordinate bond

Question 41

Dative covalent bond (coordinate bond)

Answer 41

Shared pair of electrons, in which one of the bonded atoms provides both electrons for the shared pair

Question 42

Coordination number

Answer 42

The total number of coordinate bonds formed between central metal ion and its ligands

Question 43

Monodentate ligand

Answer 43

A molecule or ion that can donate one pair of electrons to the transition metal ion to form one coordinate bond

Question 44

Bidentate ligand

Answer 44

Donate to lone pairs of electrons to the central metal ion to form two coordinate bonds

Question 45

Multidentate ligand

Answer 45

Donate more than one lone pair of electrons to the central metal ion to form more than one coordinate bond

Question 46

Optical isomer

Answer 46

Stereoisomers that are a pair of non-superimposable mirror images of each other