Does anyone know how to determine if a reaction is a redox or not? 2Ca+O2→2CaO2 is the reaction. I've already made it a balanced equation, I just need to determine if its a redox or not.
Thank you!

The reaction is included in a redox reaction

Further explanation:

Given

Reaction

2 Ca + O₂ → 2 CaO

Required

a redox reaction

Solution

Redox reactions are reactions where there is a change in oxidation number

Oxidation is an increase/increase in oxidation number, while reduction is a decrease/decrease in oxidation number.

Reducing agents are substances that experience oxidation  and oxidizing agent are substances that experience reduction

in the above reaction is included in a redox reaction because there is a change in oxidation number

Ca⇒Ca²⁺+ 2e⁻(for balanced equation : 2Ca⇒2Ca²⁺+4e⁻)

Oxidation ( 0 to +2)

O₂+2e⁻⇒O²⁻(for balanced equation : O₂+4e⁻⇒2O²⁻)

Reduction (0 to -2)

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g