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OCR A-level Chemistry A > Inorganic stuff to learn > Flashcards

Flashcards in Inorganic stuff to learn Deck (41):
1

ideal gas equation

pV=nRT p=pressure(Pa) V=volume(m3) n=no of moles R=gas constant(see data sheet) T=temp(K)(+273)

2

% uncertainty=

absolute uncertainty/measured value x100%

3

1st ionisation energy

the energy required to remove one mole of electrons from one mole of atoms in the gas phase

4

electronegativity

a measure of the ability of an atom in a molecule to attract the electrons of a shared pair to itself

5

making bleach

Cl2+2NaOH->NaCl+NaClO+H2O -disproportionation (NaClO=chloric (I) acid=bleach)

6

standard enthalpy of formation

the enthalpy change that occurs when one mole of a compound is formed from its elements in their standard states under standard conditions

7

standard enthalpy of combustion

the enthalpy change that occurs when one mole of a substance is completely burned in oxygen, converted to standard conditions

8

enthalpy change calculations

Q=mcT Q=energy(J),m=mass of water that undergoes temp change,c=specific heat capacity of water,T=temp change of water H=Q/n Q=energy(kJ),n=moles of reactant

9

dynamic equilibrium properties

conc. of reactants and products are constant
rate of forward and backward reactions are the same

10

rates: k=

rate/[A]^n[B}^m
or
ln2/half life

11

units of k

(moldm-3)^(1-n) s-1
n=overall order of reaction

12

exponential factor of Arrhenius

proportion of molecules that have sufficient energy for a reaction to take place

13

pre-exponential term of Arrhenius

accounts for frequency of collisions with correct orientation

14

Arrhenius theory

acids produce H+ in solution
bases produce OH- in solution

15

Bronsted-Lowry theory

acids donate a proton
bases accept proton

16

Lewis theory

acids accept lone pair
bases donate lone pair

17

pH=

-log[H+]

18

Relative atomic mass

The weighted mean mass of an atom of an element relative to one twelfth of the mass of an atom if carbon12

19

Empirical formula

The simplest whole number ratio of atoms of each element present in a compound

20

Molecular formula

The actual number of atoms of each element in a molecule

21

Atom economy

Mr of wanted product/total Mr of all products (×100%)

22

Structural isomerism

Same molecular formula but different structural formula
Chain, position, functional group

23

Stereoisomerism

Same structural formula but atoms occupy different positions in space
E/Z/cis/trans, optical

24

pH of weak acid

[H+]=root([HA]Ka)

25

Kw=

[H+][OH-]= 1x10-14moldm-3 at 25'C

26

pH of strong base

[H+]=Kw/[OH-]

27

Buffer solution made of:

weak acid and conjugate base

28

Methyl orange

red -> yellow, acid->alkali, 3.0-4.4

29

Bromothymol blue

yellow -> blue, acid -> alkali, 6.0-7.6

30

Phenolphthalein

colourless -> pink, acid -> alkali, 8.4-10.0

31

Conditions for electrodes

25'C, 100kPa, 1moldm-3

32

KMnO4 redox titration colour change

Purple -> colourless

33

KMnO4 redox titration ratio

1:5, MnO4:Fe

34

K2Cr2O7 redox titration colour change

Orange -> green

35

K2Cr2O7 redox titration ratio

1:6, Cr2O7:Fe

36

Colour of indicator used in K2Cr2O7 titration

violet-blue in excess K2Cr2O7

37

Thiosulphate redox titration colour

brown->colourless, fades

38

End point of thiosulphate redox

Add starch, blue black colour disappears

39

enthalpy & entropy equation

dS=dH/T

40

entropy units

JK-1mol-1

41

Gibb's free energy

dG=dH-TdS