The Grading Method:

1. Half Reaction: You don't have to check the half reactions. The Check Half Reaction in this online exercise only checks whether the atoms and charges are balanced in the half reaction. It does not necessarily mean the half reaction is correct or not. For each unbalanced atom or charge in the half reaction, 2 points will be deducted. It helps you to check the math of the atom counts which is the common mistakes that lead to an incorrect final equation.
2. Final Reaction:
• Coefficients and Species in the final reaction: points will be given for each of correct coefficients and chemical species in the final reaction. The number of points for each correct answer depends on the total number of coefficients and chemical species in the final reaction.
• H⁺ or OH^-: if the question asks for balancing the reaction in acid and you add OH^-, 4 points will be deducted; vice versa for the H⁺.
• Extra H⁺ or OH^- or H₂O or e^- incorrectly added to the final reaction: 4 points will be deducted for each.
3. Some intructors may teach you a different method in balancing equation in base. You will get a different half reaction. It's OK. It will not deduct any points from the half reaction as long as the half reactions are balanced. You will get the same final equation no matter which method you use.