Redox!

Question 1

Oxidation is -

Answer 1

The process in which electrons are LOST.
also gain of oxygen and loss of hydrogen but that’s not that important.

Question 2

Reduction is -

Answer 2

A process when electrons are GAINED.
also gain of hydrogen and loss of oxygen.

Question 3

Rules of oxidation and reduction:

Answer 3

1. All elements have an oxidation number of 0, that includes simple molecules (Cl2, O2 etc.);
2. The oxidation state of an ion is the same as its charge;
3. You know it but 123FHOC(l) with the priority highest to lowest.
   Group 1 = +1
   Group 2 = +2
   Group 3 = +3
   F = -1
   H = +1
   O = -2
   Cl = -1
   last three are with exceptions.
4. Some elements have multiple oxidation states, if so, it will be given in the name (e.g. KMnO4 - potassium manganate(VII) => the oxidation state of Manganese here is +7, etc.)

Question 4

What is a Redox reaction?

Answer 4

It’s a reaction where the processes of oxidation and reduction occur.

Question 5

Rules for balancing equations:

Answer 5

1. The symbols and number of atoms should be equal on both sides.
2. The sum of oxidation numbers on both sides should be the same.
3. The sum of charges should be the same.

Question 6

Unfortunately I am unable to provide pictures due to being a poor student so just describe what you would do to balance a Redox equation.

Answer 6

1. Identify both processes of reduction and oxidation. Note them below.
2. If there’s only an element I would balance the symbols and add electrons to the side where they are needed to balance the equation.
3. If oxygens or hydrogens are present add water or/and hydrogen ions where needed and balance them.
4. Count the charges on both sides and add electrons according to that.
5. Find the least common multiplication (I don’t know what you call it) to equal the electrons in both equations.
6. Multiply the equations by the numbers found after 5th step.
7. Move electrons out of the picture and combine both half equations together.
8. Balance the initial equation with what I have in my combination.

Question 7

Lastly for this topic - balance this equation
HNO3 + HI —> NO + I2 + H2O

Answer 7

2HNO3 + 6HI —> 2NO + 3I2 + 4H2O