Create
Learn
Share

Balancing Reactions

rename
Updated 2009-03-26 23:19

Balancing Chemical Reactions

  In each reaction below on the left, several coefficients are missing.

The coefficients in the right column fill in the blanks in the left column.

All coefficients have been rescaled to be the lowest possible integers.

 

  While you could try to memorize all these reactions and their coefficients,
it is better to use these as practice examples.
Just make sure the quantities of each element on the left side of each equation
match the quantities of each element on the right side of each equation.

 

3 H2O contains 6 H atoms and 3 O atoms,
5 Fe2O3 contains 10 Fe atoms and 15 O atoms, and

3 NiCl2•6H2O contains 3 Ni atoms, 6 Cl atoms, 36 H atoms, and 18 O atoms.

 

ReactionMissing Coefficients
___ N2(g) + ___ H2(g) -> ___ NH3(g)1, 3, 2
___ H2(g) + ___ CO(g) -> ___ CH3OH(l)2, 1, 1
___ S(s) + ___ O2(g) -> ___ SO2(g)1, 1, 1
___ SO2(g) + ___ O2(g) -> ___ SO3(g)2, 1, 2
___ SO3(g) + ___ H2O(l) -> ___ H2SO4(aq)1, 1, 1
___ NO(g) + ___ O2(g) -> ___ NO2(g)2, 1, 2
___ Ni(s) + ___ CO(g) -> ___ Ni(CO)4(g)1, 4, 1
___ Ag(s) + ___ S8(s) + heat -> ___ Ag2S(s)16, 1, 8
___ Na(s) + ___ Cl2(g) -> ___ NaCl(s)2, 1, 2
___ Al(s) + ___ I2(s) -> ___ AlI3(s)1, 3, 2
memorize

 

ReactionMissing Coefficients
___ NH4NO2(s) + heat -> ___ N2(g) + ___ H2O(g)1, 1, 2
___ KClO3(s) + heat -> ___ KCl(s) + ___ O2(g)2, 2, 3
___ HgO(s) + heat -> ___ Hg(l) + ___ O2(g)2, 2, 1
___ MO(s) + ___ CO2(g) -> ___ MCO3(s)1, 1, 1
___ NH4NO3(s) + heat -> ___ N2O(g) + ___ H2O(g)1, 1, 2
___ N2(g) + ___ O2(g) + heat -> ___ NO(g)1, 1, 2
___ NO(g) + ___ O2(g) -> ___ NO2(g)2, 1, 2
___ N2(g) + ___ O2(g) -> ___ NO2(g)1, 2, 2
___ Xe(g) + ___ F2(g) -> ___ XeF4(s)1, 2, 1
___ C(s) + ___ O2(g) -> ___ CO2(g)1, 1, 1
memorize

 

ReactionMissing Coefficients
___ B(s) + ___ H2(g) -> ___ B2H6(g)2, 3, 1
___ B(s) + ___ O2(g) -> ___ B2O3(s)4, 3, 2
___ H2(g) + ___ O2(g) -> ___ H2O(l)2, 1, 2
___ CH4(g) -> ___ C(s) + ___ H2(g)1, 1, 2
___ CO(g) + ___ H2(g) -> ___ CH3OH(l)1, 2, 1
___ C(s) + ___ O2(g) -> ___ CO(g)2, 1, 2
___ HI -> ___ I2 + ___ H22, 1, 1
___ H2(g) + ___ M(s) -> ___ MH2(s)1, 1, 1
___ C6H12O6 -> ___ C2H5OH + ___ CO21, 2, 2
___ SO3(g) + ___ H2O(l) -> ___ H2SO4(aq)1, 1, 1
___ S(s) + ___ O2(g) -> ___ SO3(g)2, 3, 2
___ SO2(g) + ___ O2(g) -> ___ SO3(g)2, 1, 2
___ S(s) + ___ O2(g) -> ___ SO2(g)1, 1, 1
memorize

 

ReactionMissing Coefficients
___ N2O5(g) + ___ H2O(l) -> ___ HNO3(l)1, 1, 2
___ N2(g) + ___ O2(g) -> ___ N2O5(g)2, 5, 2
___ C(s) + ___ H2(g) -> ___ C2H2(g)2, 1, 1
___ NO(g) + ___ O(g) -> ___ NO2(g)1, 1, 1
___ C6H4(OH)2(aq) -> ___ C6H4O2(aq) + ___ H2(g)1, 1, 1
___ H2(g) + ___ O2(g) -> ___ H2O2(aq)1, 1, 1
___ H2(g) + ___ O2(g) -> ___ OH(g)1, 1, 2
___ O(g) + ___ H(g) -> ___ OH(g)1, 1, 1
___ Na(s) + ___ O2(g) -> ___ Na2O(s)4, 1, 2
___ SO3(g) + ___ H2O(l) -> ___ H2SO4(aq)1, 1, 1
___ H2(g) + ___ Cl2(g) -> ___ HCl(g)1, 1, 2
___ H2(g) + ___ O2(g) -> ___ H2O(g)2, 1, 2
___ Xe(g) + ___ F2(g) -> ___ XeF2(s)1, 1, 1
___ NiCl2•6H2O(s) -> ___ NiCl2(s) + ___ H2O(g)1, 1, 6
memorize

 

Balancing Reactions 2 has more examples.

 

Reference: Chapters 3-6 of "Chemistry" by Steven S. Zumdahl, 1986,
D. C. Heath and Company (ISBN=0-669-04529-2).

Recent badges