Balancing Reactions worksheetBalancing chemical reactions is an important part of our study of chemistry. Below are listed a few unbalanced chemical reactions and some information about each reaction. Use your dry-ink erase board to balance these reactions BEFORE you transfer the correct answer to this worksheet.

Methane burns. Methane combines with oxygen in the air to make carbon dioxide and water vapor.

___CH4(g) + ___O2(g) ___CO2(g) + ___H2O(g)

A silver spoon tarnishes. The silver reacts with sulfur in the air to make silver sulfide, the black material we call tarnish.

___Ag(s) + ___S(g) ___Ag2S(s)

An iron bar rusts. The iron reacts with oxygen in the air to make rust.

___Fe(s) + ___O2(g) ___Fe2O3(s)

An antacid (calcium hydroxide) neutralizes stomach acid (hydrochloric acid).

___Ca(OH)2 + ___HCl ___CaCl2 + ___H2O

Glucose (simple sugar) ferments to ethyl alcohol and carbon dioxide. The sugar in grapes or from grain ferments with yeast to make the alcohol and carbon dioxide. The carbon dioxide is the gas that bubbles out of beer or Champaign.

___C6H12O6 (glucose) ___C2H5OH (ethyl alcohol) + ___CO2

You should have a good idea of how to do these problems. Now all you need to do is practice, practice, practice. Flip the sheet over and get started!!!

Decomposition reactions

___HgO(s)___Hg(l) +___O2(g)

___FeS(s)___Fe(s) +___S(s)

___Ba(ClO3)2(s)___BaCl2(s) +___O2(g)

Synthesis reactions

___Mg(s) +___O2(g)___MgO(s)

___K(s)+___Cl2(g)___KCl(s)

___Fe(s) +___O2(g)___Fe2O3(s)

Single replacement reactions

___Ca(s) +___H2O(l)___Ca(OH)2(s) +___H2(g)

___Zn(s) +___HCl(aq)___ZnCl2(s) +___H2(g)

___Cl2(g) +___NaBr(s)___NaCl(s) +___Br2(l)

Double replacement reactions

___KOH(aq) +___H2SO4(aq)___K2SO4(aq) +___H2O(l)

___FeS(aq) +___HCl(aq)___FeCl2(aq) +___H2S(g)

___NaCl(aq) +___H2SO4(aq)___Na2SO4(aq) +___HCl(aq)

Combustion reactions

___C2H6(g) +___O2(g)___CO2(g) +___H2O(g)

___C2H5OH(l) +___O2(g)___CO2(g) +___H2O(g)

H2CO3(aq) CO2 + H2O: Is this combustion? Explain.

What’s special about these reactions? Balance them and then use the space below to explain your answer.

___CaCO3(aq) +___HCl(aq)___CaCl2(s) +___CO2(g) +___H2O(l)

___K2SO3(aq) +___HNO3(aq)___KNO3(aq) +___SO2(g) +___H2O(l)

___NH4Cl(aq) +___NaOH(aq)___NaCl(aq) +___NH3(l) +___H2O(l)

Really hard ones that I would never assign on a test

___(NH4)2Cr2O7(s) ___Cr2O3(s) +___N2(g) +___H2O(l)

___I4O9(s) ___I2O6(s) +___I2(l) +___O2(g)

___Al(s) +___NaOH(aq) +___H2O(l) ___NaAl(OH)4(aq) +___H2(g)