Acidic has the steps of balancing half rxns, adding H2O to balance O’s, then adding H’s to balance the H’s from the H2O, then adding electrons to balance the charges to match the sides of each half rxns, ending with balancing everything and creating a net eq with no electrons (but still have left over water and H atoms)
Basic continues off from this by adding hydroxides to “counter” the leftover protons from the acidic step. This ultimately forms water, (H+OH) and if there is water on both sides you can cancel them out and receive the net equation.
Now this is the way that I thought about it when I came across these cards, I personally like the way they are as it gets you to think. However if you want a more streamlined approach check below:
Half-Equation Method to Balance redox Reactions in Acidic Aqueous Solutions
Each reaction is balanced by adjusting coefficients and adding H2O, H+, and e− in this order:
1-Balance elements in the equation other than O and H.
2-Balance the oxygen atoms by adding the appropriate number of water (H2 ) molecules to the opposite side of the equation.
3-Balance the hydrogen atoms (including those added in step 2 to balance the oxygen atom) by adding H+ ions to the opposite side of the equation.
4-Add up the charges on each side. Make them equal by adding enough electrons ( e−) to the more positive side. (Rule of thumb: e− and H+ are almost always on the same side.)
5-The e− on each side must be made equal; if they are not equal, they must be multiplied by appropriate integers (the lowest common multiple) to be made the same.
6-The half-equations are added together, canceling out the electrons to form one balanced equation. Common terms should also be canceled out.
7-The equation can now be checked to make sure that it is balanced.
Half-Equation Method to Balance redox Reactions in Basic Aqueous Solutions
If the reaction is being balanced in a basic solution, the above steps are modified with the addition of one step between #3 and #4:
3b Add the appropriate number of OH−to neutralize all H+ and to convert into water molecules.
The cards could technically be fused together and just ask what the steps would be if it was basic, but it feels like its better the way they are. (although writing it out the way I just took it from chem libre sounds better lol)
Theres another card that shows this same reaction in acid, look at it