Balance this equation using the smallest whole-number coefficients: __ CH₄ + __ O₂ → __ CO₂ + __ H₂O. What is the sum of all the coefficients?
Answer and explanation
6
CH₄ + 2 O₂ → CO₂ + 2 H₂O: 1 + 2 + 1 + 2 = 6
Subjects
Chemical reactions in Chemistry
Choose questions individually, practise online, or create a worksheet with matching answers. Counts include generated variants, not only authored originals.
Make a worksheet227 question instances
Sample exercises
Classify this reaction: Fe + CuSO₄ → FeSO₄ + Cu
- combustion
- synthesis
- single displacement
- decomposition
Answer and explanation
single displacement
Single displacement: an element replaces another element in a compound (A + BC → AC + B).
In a sealed container, 19.1 g of A and 19.4 g of B react until B is used up. 13.4 g of A is left over, and the only product is C. What mass of C forms?
Answer and explanation
25.1 g
19.1 + 19.4 − 13.4 = 25.1
Study notes
Balancing chemical equations
Study guide for Grades 9 to 12: 2 worked examples and 2 practice questions. Atoms are rearranged, not created or destroyed, so each element must appear the same number of times on both sides.
Grades 9–12Classifying chemical reactions
Study guide for Grades 9 to 12: 2 worked examples and 2 practice questions. Compare the number and kind of reactants and products, then match the pattern.
Grades 9–12Conservation of mass in reactions
Study guide for Grades 9 to 12: 2 worked examples and 2 practice questions. Atoms are only rearranged in a reaction, so mass is conserved. If mass seems to change, a gas has escaped or been taken in from the air.
Grades 9–12Chemical reactions · Quick reference
Reference sheet for Grades 9 to 12: balancing chemical equations, classifying chemical reactions and conservation of mass in reactions. Atoms are rearranged, not created or destroyed, so each element must appear the same number of times on both sides.
Grades 9–12