Look at the reactants and products. Which of the 5 reaction patterns is this?
Enter the oxidation charge for each element or polyatomic group below. (Use periodic table group or Roman numeral).
Input atom counts start at 0. Step up coefficients (+ / −) following the order: Metals → Nonmetals → Hydrogen → Oxygen.
Balancing Order: Metals (Mg: 1=1) → Nonmetals (Cl: need 2 on left) → Hydrogen (H: 2=2).
Complete Answer: 1 Mg + 2 HCl → 1 MgCl₂ + 1 H₂ (Single Replacement)
Expected Charges: Mg (+2), H (+1), Cl (-1)
Coaching Tip: Remind your student that hydrogen gas must always be written as H₂, not H.
General Formula: A + BX → AX + B