Chemical Equation Balancer

Balance any chemical equation instantly. Uses linear algebra - no AI required. Free to use.

Try these examples (click to balance):

CBSE-12-CHEM-CH4 · 5-Step Ion-Electron & Electron-LCM WorkbenchNCERT Part 1 · Ch 4 Section 4.4.1 (K2Cr2O7 Oxidizing Action)

Interactive Acidic & Basic Medium Redox Half-Reaction & Electron-LCM Stepper

Step through oxidation state changes, skeletal half-reactions, acidic (H+) vs alkaline (OH-) medium rules, Least Common Multiple (LCM) electron cancellation, and atom-by-atom plus net-charge conservation. 100% deterministic local engine with zero runtime AI.

Select Canonical CBSE Class XII d-Block Redox System (5 Board Reactions)

Step 1 · Oxidation State Change & n-Factor IdentificationOrange to Green

Reduction Half (Oxidizing Agent)

Cr(+6) -> Cr(+3) (2 Cr atoms x 3e- = 6e- gain)

n-factor = 6e- per formula unit

Oxidation Half (Reducing Agent)

Fe(+2) -> Fe(+3) (1e- loss per Fe^2+)

n-factor = 1e- per formula unit

Equivalent Weight Link: E(K2Cr2O7) = M / 6 = 294.185 / 6 = 49.0308 g/eq

Step 2 · Skeletal Oxidation & Reduction Half-Reactions

Skeletal Reduction Half-Reaction

Cr2O7^2- -> 2Cr^3+

Skeletal Oxidation Half-Reaction

Fe^2+ -> Fe^3+

Step 3 · Oxygen (H2O) & Hydrogen (H+ vs OH-) Medium BalanceAcidic medium (H2SO4)

Acidic medium (H2SO4): Balance 7 O atoms in Cr2O7^2- by adding 7 H2O to the right side, then balance 14 H atoms by adding 14 H+ to the left side.

Medium-Balanced Reduction Half: Cr2O7^2- + 14H+ + 6e- -> 2Cr^3+ + 7H2O

Medium-Balanced Oxidation Half: Fe^2+ -> Fe^3+ + e-

Board Trap: Cr2O7^2- contains TWO Cr(+6) atoms. Students often write n-factor = 3 instead of 2 x (6 - 3) = 6e-.

Step 4 · Electron (e-) Charge Balance & LCM Multiplier CommitTarget LCM = 6e-

Test your Least Common Multiple (LCM) electron count to equalize electrons gained and lost before summing the half-reactions:

Electron Balance Verified (LCM = 6e-)

Verified LCM = 6e-. Reduction half-reaction (6e-) scales by x1 and Oxidation half-reaction (1e-) scales by x6 so electrons cancel cleanly.

Scaled Reduction: Cr2O7^2- + 14H+ + 6e- -> 2Cr^3+ + 7H2O (x 1)

Scaled Oxidation: 6Fe^2+ -> 6Fe^3+ + 6e- (1e- x 6)

Step 5 · Atom-by-Atom & Net-Charge Conservation Matrix (Left Side = Right Side)All 5 Checks Balanced (Net Charge +24 = +24)

Verified Net Ionic Equation (Acidic medium (H2SO4))

Cr2O7^2- + 6Fe^2+ + 14H+ -> 2Cr^3+ + 6Fe^3+ + 7H2O

Atom / Charge	Left Side (Reactants)	Right Side (Products)	Left Side = Right Side
Cr	1 x Cr2O7^2- (2)	2 x Cr^3+ (2)	2 = 2
Fe	6 x Fe^2+ (6)	6 x Fe^3+ (6)	6 = 6
O	1 x Cr2O7^2- (7)	7 x H2O (7)	7 = 7
H	14 x H+ (14)	7 x H2O (14)	14 = 14
Net Charge	(-2) + 6(+2) + 14(+1) = +24	2(+3) + 6(+3) + 0 = +24	+24 = +24

Aligned to the CBSE Class XII Chemistry syllabus. Not affiliated with or endorsed by CBSE. Official NCERT coordinates are locator metadata only.

How to Balance Chemical Equations

Our equation balancer uses matrix algebra to find the smallest whole-number coefficients that satisfy conservation of mass. Enter any equation using standard chemical notation with arrows (-> or →).

Supported Formats

Simple: Fe + O2 -> Fe2O3
Parentheses: Ca(OH)2 + HCl -> CaCl2 + H2O
Complex: K4[Fe(CN)6] + H2SO4 + H2O -> K2SO4 + FeSO4 + (NH4)2SO4 + CO