Redox

Question 1

Acronym for acid solution half equation order:-

Answer 1

CaWHe

Ca- central atom.
W- water.
H- H+
e- electrons

Question 2

Acronym for half equation order alkaline solution:-

Answer 2

CaWHOHe

Same as acid, OH = OH-

Question 3

Conwtructing half equation:-

Answer 3

Balance central atom.
Balance O w/ H2O.
Balance H w/ H+ on one side.
If alk, add same no of OH- to both sides as number of H+.
Balance charges w/ e-.
Balance by cancelling H2O molecules in alkaline.

Question 4

Combining half equations:-

Answer 4

Multiply equations to get equal numbers of electrons in both.
Add together.
Cancel out anything that appears on both sides.

Question 5

Oxidation state by experiment:-

Answer 5

Do half equation for substance you do know state.
Calc reacting moles.
Moles of electrons gained by known = unknown lost- multiply known by final state of unknown. Divide mol of electrons (just calced) by mol of substance to get moles of electrons lost per mol of ions. Final state minus number just calced = initial state.