Student Chemistry FAQ: How Do You Write and…

How Do You Write and Balance Half-Equations for Redox Reactions?

Write the reactant and product, balance every element, and then add electrons so that the total charge is equal on both sides. A valid half-equation must conserve both atoms and charge.

This method is required for IB Chemistry SL and HL under Reactivity 3.2, electron transfer reactions.

The balancing method

Step	What to do
1	Identify the species being oxidized or reduced and write the incomplete half-equation.
2	Balance all elements except oxygen and hydrogen.
3	Balance oxygen atoms by adding water, $\text{H}_2\text{O}$ .
4	In acidic solution, balance hydrogen atoms by adding $H^{+}$ .

How Do You Write and Balance Half-Equations for Redox Reactions?

Write the reactant and product, balance every element, and then add electrons so that the total charge is equal on both sides. A valid half-equation must conserve both atoms and charge.

This method is required for IB Chemistry SL and HL under Reactivity 3.2, electron transfer reactions.

The balancing method

Step	What to do
1	Identify the species being oxidized or reduced and write the incomplete half-equation.
2	Balance all elements except oxygen and hydrogen.
3	Balance oxygen atoms by adding water, $\text{H}_2\text{O}$ .
4	In acidic solution, balance hydrogen atoms by adding $H^{+}$ .

How Do You Write and Balance Half-Equations for Redox Reactions?

The balancing method

How Do You Write and Balance Half-Equations for Redox Reactions?

The balancing method

MYP Subjects

Exam technique