Chemistry E,e&e

Front 1

How do temperature, pressure and concentration affect Kc?

Back 1

Temperature - dependant on exothermic/endothermic reaction. Kc increases with temperature if reaction is endothermic.

Pressure and Concentration - Le Chatilier's principle reduces changes in pressure and concentration so Kc is unaffected.

Front 2

How do conjugate acid-base pairs work?

Back 2

An acid loses a proton to form its conjugate base. The base accepts the proton to form its conjugate acid.

Front 3

Define Ka

Back 3

Front 4

Define Rate of Reaction

Back 4

– Change of concentration of a reactant of product per unit time.

Front 5

Define half-life

Back 5

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

Front 6

What is the rate determining step

Back 6

The slowest step in the reaction mechanism of a multi-step reaction

Front 7

How do you find pKa?

Back 7

-log(Ka)

Front 8

What is a buffer solution?

Back 8

A system thatminimises pH changes on addition of smallamounts of an acid or a base.

Front 9

How do you find the[H+] value of a buffer solution?

Back 9

Kacidoversalt

Front 10

Define Lattice Enthalpy

Back 10

The enthalpy change that accompanies the formation of 1 mole of ionic compounds from its gaseous ions under standard conditions.

Front 11

Standard Enthalpy of formation

Back 11

One mole of a compound formed from its constituent elements in their standard states.

Front 12

Standard enthalpy of atomisation

Back 12

One mole of gaseous atoms formed from its element in standard states.

Front 13

First ionisation energy

Back 13

Energy needed to form 1 mole of gaseous 1+ atoms through the removal of 1 mole of electrons from an atom in its gaseous state.

Front 14

First electron affinity

Back 14

Energy needed to form 1 mole of gaseous 1- atoms through the addition of 1 mole of electrons from an atom in its gaseous state

Front 15

Standard enthalpy change of solution

Back 15

Enthalpy change when one mole of a compound is completely dissolved in water under standard conditions.

Front 16

Standard Enthalpy change of hydration

Back 16

Enthalpy change when one mole of isolated gaseous ions is dissolved in water forming one mole of aqueous ions under standard conditions.

Front 17

What affects enthalpy and how so?

Back 17

Charge - Greater charges have a stronger attractive force so there is less ionic radius so the lattice enthalpy is more negative and more exothermic.

Ionic radius- greater ionic radius means less attraction so lattice enthalpy is greater and less exothermic.

Front 18

What is entropy

Back 18

A measure of the‘disorder’ of a system. The system becomes energetically more stable when itbecomes more disordered.

Front 19

How do you find entropy and what does its value mean?

Back 19

Front 20

How can we find if a reaction is feasible?

Back 20

∆G = ∆H - T∆S

the more negative ∆G, the more feasible the reaction.

Front 21

Write the equation and observations for precipitate reaction of Cu2+

Back 21

Cu2+(aq) + 2OH-(aq) ---> Cu(OH)2 (s)

pale blue solution ---> blue precipitate.

Front 22

Write the equation and observations for precipitate reaction of Co2+

Back 22

Co2+(aq) + 2OH-(aq) ---> Co(OH)2 (s)

Pink Solution ---> Blue precipitate

(Beige in presence of air)

Front 23

Write the equation and observations for precipitate reaction of Fe2+

Back 23

Fe2+(aq) + 2OH-(aq) ---> Fe(OH)2 (s)

Pale green solution ---> Green precipitate

(rusts in presence of air)

Front 24

Write the equation and observations for precipitate reaction of Fe3+

Back 24

Fe3+(aq) + 3OH-(aq) ---> Fe(OH)3 (s)

Pale yellow solution ---> Rusty brown solution

Front 25

What is a ligand?

Back 25

A molecule or ion that can donate a pair of electrons with the transition metal ion to forma coordinate bond.

Front 26

What is cis-platin and how is it used in cancer treatment?

Back 26

Cis-platin is the cis complex of [PtCl2(NH3)2]

Cis-platin binds to the DNA of thecancerous cells preventing them from reproducing. This leads to thedeath of the cancer containing cells.

Front 27

Give an example of ligand substitution where the coordination number and shape do not change, with observations. Why do these properties not change?

Back 27

[Co(H2O)6]2+ + 6NH3 <==> [Co(NH3)6]2+ + 6H2O

octahedral pink octahedral pale brown

The ligands are similar size so easily substitute without changing.

Front 28

Give an example of ligand substitution where the coordination number and shape change, with observations. Why do these properties change?

Back 28

[Co(H2O)6]2+ + 4Cl- <==> [CoCl4]2- + 6H2O(l)

octahedral pink tetrahedral blue

[Cu(H2O)6]2+ + 4Cl- <==> [CuCl4]2- + 6H2O(l)

octahedral pale blue tetrahedral yellow

The ligands are different sizes e.g: H2O Cl-

Front 29

Give an example of partial ligand substitution, with observations.

Back 29

octahedral pale blue elongated octahedral deep blue

[Cu(H2O)6]2+ + 4NH3 <=> [Cu(NH3)(H2O)2]2+ + 4H2O