Home / Subjects and practice assessments / Science English · United Kingdom · Free printable sample
Balancing chemical equations Try these questions and check the worked answers. Choose a skill for targeted practice or combine skills in a unit assessment.
Levels indicate approximate learning stages, not certified alignment with a country’s curriculum. Choose by the skills the learner is studying.
WorksheetWise · Standard · 1097
Balancing chemical equations Work through each question. Show your reasoning where space is provided.
Name: ____________________ · Date: ____________
1. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: N2 + H2 → NH3
2. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: C2H6 + O2 → CO2 + H2O
3. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: H2O2 → H2O + O2
4. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: CH4 + O2 → CO2 + H2O
5. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: H2 + O2 → H2O
WorksheetWise · en-gb · 1/1 WorksheetWise · Standard · 1097
Balancing chemical equations — Answer key Work through each question. Show your reasoning where space is provided.
1. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: N2 + H2 → NH3
1 N2 + 3 H2 → 2 NH3
Coefficients, in order: 1, 3, 2. Each element has the same total number of atoms on both sides.
2. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: C2H6 + O2 → CO2 + H2O
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
Coefficients, in order: 2, 7, 4, 6. Each element has the same total number of atoms on both sides.
3. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: H2O2 → H2O + O2
2 H2O2 → 2 H2O + 1 O2
Coefficients, in order: 2, 2, 1. Each element has the same total number of atoms on both sides.
4. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: CH4 + O2 → CO2 + H2O
1 CH4 + 2 O2 → 1 CO2 + 2 H2O
Coefficients, in order: 1, 2, 1, 2. Each element has the same total number of atoms on both sides.
5. Balance using the smallest positive whole-number coefficients, including 1. Keep every chemical formula unchanged: H2 + O2 → H2O
2 H2 + 1 O2 → 2 H2O
Coefficients, in order: 2, 1, 2. Each element has the same total number of atoms on both sides.
WorksheetWise · en-gb · 1/1 Mathematics Phonics Spelling Grammar Secondary mathematics Science Accounting Geography Computing Advanced mathematics Reading History Practice assessments About these resources WorksheetWise authors these practice questions and translations. Numerical answers are checked by automated tests. Reading and history include marking guidance. These materials have not been independently certified by an exam board.
For UK families, tutors and classrooms. A4 paper is selected initially. Use these maths activities alongside the current lesson; Year groups and expectations differ across the UK, and no national curriculum alignment is claimed.