Ch 10 - (Redox Reactions) Flashcards
What is a redox reaction?
When oxidation and reduction take place together at the same time.
What is oxidation?
Gain of oxygen (when O2 is added)
What is reduction?
Loss of oxygen (when O2 is removed)
What does the roman numeral written after the number refer to?
The oxidation number of an element.
What can redox reaction also be defined as?
Electron transfer
Define oxidation.
Oxidation is the reaction in which an elements, ion, or compound loses electrons
What happens to the oxidation number due to oxidation?
- Oxidation number increases.
- Shown in half equation
Ag –> Ag+ + e-
Define reduction.
Reduction is the reaction in which an element, ion, or compound gains electrons
What happens to the oxidation number due to reduction?
- Oxidation number is decreased
- Half equation
O2 + 4e –> 202-
Why are spectator ions?
That do not change or take part in the reaction.
What is OIL RIG?
O - Oxidation
I - is
L - Loss of electrons
R - Reduction
I - is
G - gain of electrons
What is oxidation number?
A number assigned to an atom or ion in a compound which indicates the degree of oxidation (reduction)
What does oxidation number show?
It shows the number of electrons that an atom has lost, gained, or shared in forming a compound.
What does the oxidation number help keep track of?
It helps you keep track of the movement if electrons in a redox process.
How is oxidation number written as?
+/- sign followed by a number ( not to be confused with a charge which is written by a number followed by + / - )
When can redox reaction be identified?
The changes in oxidation number when a reactant goes to a product.
How can we test for redox reactions?
Involve the observation of a color change.
Hats re two examples of identifying color change in redox reactions?
- Acidified potassium manganate (VII)
- Potassium iodide
- Potassium manganate (VII), KMnO4 is an oxidising agent which tests for the presence of reducing agents.
What happens when acidified potassium manganate (VII) is added to a reducing ageng?
Color changes from purple to colorless
What is potassium iodide? KI?
A reducing agent which is often used to test for the presence of oxidising agents.
What happens when acidified solution of an oxidising agent such as aqueous chlorine or hydrogen peroxide (H2O2)
- turns red brown due to the formation of I2
- Potassium iodide is oxidised as it loses electron and peroxide is reduced, therefore potassium iodide is a reducing agent.
What is an oxidising agent?
A substance that oxidises another substance, and becomes reduced in the process.
What happens in an oxidising agent?
An oxidising agent agent gains electrons as another substance loses electrons
What is an example of an oxidising agent?
Hydrogen peroxide, fluorine and chlorine
Define a reducing agent.
A substance that reduces another substance, and becomes oxidised in the process.
What happens in a reducing agent?
Loses electrons as another substance gains electrons.
What’s are examples of reducing agents?
Carbon and oxygen.
Why is reduction very important in chemical industry?
To extract metal from metal ores.
