A Redox Reaction (or oxidation/reduction reactions) is a reaction in which electrons are transferred.
Oxidation Number refers to the number of electrons added to or removed from an element.
Oxidation Number refers to the number of electrons added to or removed from an element.
- Oxidation loses one or more electrons and the oxidation number increases.
- Reduction gains one or more electrons and the oxidation number decreases.
Oxidation Rules:
Hydrogen = 1
4. In compounds:
Flourine = -1
5. In an ionic compound, the following elements will equal its charge as its oxidation number:
Group 1A, 2A, Ag, Zn, and Al
6. The sum of oxidation states will equal 0 in compounds and the charge of the ion
- The oxidation state of an atom in a single element is equal to 0
- A monoatomic ion always uses its charge as its oxidation state
- In covalent compounds:
Hydrogen = 1
4. In compounds:
Flourine = -1
5. In an ionic compound, the following elements will equal its charge as its oxidation number:
Group 1A, 2A, Ag, Zn, and Al
6. The sum of oxidation states will equal 0 in compounds and the charge of the ion
Let's find the oxidation number of the bolded element:
Now let's identify which redox equation has been oxidized or reduced!
2. 2 Rb + 3 F2 → 2 RbF
This is not a redox reaction because the electrons aren't transferred or changed.
3. CaCO3 → CaO + CO2
Calcium decreases from +3 to +2 making it a reduction. Meanwhile Carbon has been oxidized.
4. 2 K + Zn(NO3)2 → Zn + 2 KNO3
Kn has been reduced and K has been oxidized.
- I2 would have an oxidation number of 0 because it is a single element.
- HMnO4: In this, we multiply -2 (for the oxygen) and 4 to get -8. Hydrogen has +1, then we do simple math from here:-8 + 1 = -7. Mn must be +7 in order for the whole thing to equal 0.
- NaNO2: -4 + 1 = 3, so N must be -3
Now let's identify which redox equation has been oxidized or reduced!
- 1 C10H8 + 7 O2 → 5 CO2 + 4 H2O
2. 2 Rb + 3 F2 → 2 RbF
This is not a redox reaction because the electrons aren't transferred or changed.
3. CaCO3 → CaO + CO2
Calcium decreases from +3 to +2 making it a reduction. Meanwhile Carbon has been oxidized.
4. 2 K + Zn(NO3)2 → Zn + 2 KNO3
Kn has been reduced and K has been oxidized.