Defenitions rates, equilibrium and ph

Question 1

Rate of reaction

Answer 1

Change in concentration of reactant it product per unit time

Question 2

Initial rate of reaction

Answer 2

Change in concentration of a reactant or product per unit time at the start of a reaction, t=0

Question 3

What is order?

Answer 3

Order with respect to reactants if the power to which the concentration of the reactant is raised in the rate equation

Question 4

Overall order

Answer 4

Sum of all individual orders

Question 5

Rate constant, k

Answer 5

Constant that links the rate of reaction with the concentrations of the reactants raider to powers of their orders in the rate equation

Question 6

Half life

Answer 6

The time taken for the concentration of the reactant to reduce by half

Question 7

Reaction mechanism

Answer 7

A series of steps that make up overall reaction

Question 8

Rate determining step

Answer 8

Slowest step in the reaction mechanism of a multi step reaction

Question 9

Intermediate

Answer 9

A species formed in one step of a multi-step reaction that is used in a subsequent step and is not seen as either a reactant or a product if the overall equation

Question 10

Dynamic equilibrium

Answer 10

Exists in a closed system, where the rate if the forward reaction is equal to the rate of the reverse reaction

Question 11

Homogenous equilibrium p

Answer 11

Equilibrium in which all species are making up the reactants and products are in the same physical state

Question 12

Heterogenous equilibrium

Answer 12

An equilibrium in which species making up reactants and products are in different physical states

Question 13

Concentration

Answer 13

Mol/vol

Question 14

Kc

Answer 14

Equilibrium constant
(Products)^balancing numbers/(reactants)^balancing numbers

Question 15

Brønsted-Lowry acid

Answer 15

A proton, H+ donor

Question 16

Brønsted-Lowry base

Answer 16

A proton acceptor

Question 17

Alkali

Answer 17

A base that dissolves in water forming OH- ions

Question 18

Neutralisation

Answer 18

Chemical reaction in which acid and base react to produce a salt and water

Question 19

Acid base pair

Answer 19

Two species that transform into each other by gain or loss of a proton

Question 20

pH

Answer 20

-log(H+

Question 21

H+

Answer 21

10^-pH

Question 22

Strong acid

Answer 22

Acid that completely dissociates in solution

Question 23

Weak acid

Answer 23

Acid that partially dissociates in solution

Question 24

COD dissociation constant

Answer 24

Extent of acid dissociation

Ka = (H+)(A-)/(HA)

Question 25

Ka

Answer 25

10-pKa

Question 26

pKa

Answer 26

-log(Ka

Question 27

Strong acid calculation

Answer 27

(H+)=(HA)

Question 28

Weak acid calculation

Answer 28

H+ = sq root Ka x (HA)

Question 29

Ionic product of water

Answer 29

Kw= (H+)(OH-)

Controls balance between H and OH in all aqueous solutions

Question 30

Value of Kw at 25 degrees

Answer 30

1x10-14 mol2dm-6

Question 31

pH of strong base

Answer 31

(OH)=(base)

H+ = Kw/OH-

Question 32

Buffer solution

Answer 32

Mixture that minimises pH changes in addition if small amounts of acid or base

Question 33

Buffer calculations

Answer 33

H+ = Ka x HA/A-

Question 34

Equivalence point

Answer 34

Point in a titration at which the volume of one solution has reacted exactly with the volume of the second solution

Question 35

End point

Answer 35

Point in a titration at which there are equal concentrations of weak acid and conjugate base forms of the indicator, colour at endpoint midway between acid and base colours

Question 36

Standard enthalpy change of neutralisation

Answer 36

Energy change that accompanies the neutralisation of an aqueous acid by an aqueous base to form one mole of water under standard conditions