Redox

Question 1

Biochemical oxygen demand

Answer 1

the amount of oxygen used by the aerobic microorganisms in water to decompose the organic matter in the water over a fixed period of time at a fixed temperature

Question 2

Cathode

Answer 2

The electrode at which reduction occurs

Question 3

Oxidising agent

Answer 3

accepts electrons and become REDUCED

Question 4

Reducing agent

Answer 4

donate electrons and become OXIDIZED. eg: most metals

Question 5

Standard electrode potential

Answer 5

a half-cell is its electrode potential relative to a hydrogen half-cell, measured under standard conditions:

1. Pressure 100 kPa
2. Temperature 298K
3. all substances pure
4. all solutions a 1m
5. platinum plating on the hydrogen electrode with a roughened surface

Question 6

oxidation and reduction

Answer 6

OILRIG 
O xygen 
I s
L oss
R eduction
i s 
G ain

Question 7

electrolysis

Answer 7

The breaking down of a substance (in molten state or solution) by the passage of electricity through it

Question 8

electrolyte

Answer 8

A solution or molten compound, that will conduct electricity with decomposition at the electrodes as it does so; electrolytes contain ions that are free to move towards the electrodes.

Question 9

Electroplating

Answer 9

the process of coating an object with a thin layer of a metal using electrolysis

Question 10

standard cell potential

Answer 10

Is the EMF (voltage) produced when two half-cells are connected under certain conditions. This drives the movement of electrons through the external circuit from the negative electrode to the positive electrode.

Question 11

Standard electrode potential

Answer 11

The emf (voltage) of a half cell connected to a standard hydrogen electrode, measured under standard conditions; all solutions must be of concentration 1 mol dm-3

Question 12

Standard hydrogen electrode

Answer 12

The half cell relative to which standard electrode potential are measured.