Writing and Balancing Chemical Equations Answer Key (CHEM 1405)

Back to Chemistry 1405 Practice Problems

 

Read each statement. 

Write the correct formula for the substance indicated

Replace each “and” or “plus” with the symbol “+”.

Replace each phrase indicating change (make, produces, yield, etc.) with an arrow pointing toward the right. 

Balance each equation.  Show work if necessary.

 

Example:

Lead II nitrate and potassium carbonate produce lead II carbonate and potassium nitrate.

Pb(NO3)2     +      K2CO3         Arrow-1.png         PbCO3    +    KNO3

                               Pb-1                                                       Pb-1

                               N-2                                                         N-1

                               O-9                                                         O-6

                               K-2                                                          K-1

                               C-1                                                          C-1

 

  1. aluminum and oxygen make aluminum oxide

4Al     +     3O2     Arrow-2.png     2Al2O3    

 

 

  1. sodium hydroxide and sulfuric acid produce sodium sulfate and water

2NaOH     +     H2SO4     Arrow-2.png     Na2SO4     +    2H2O

 

 

  1. iron and copper II chloride make iron II chloride and copper

Fe     +     CuCl2     Arrow-2.png     FeCl2     +     Cu      (Already balanced)

 

 

  1. potassium chlorate decomposes into potassium chloride and oxygen

2KClO3     Arrow-2.png     2KCl     +     3O2

 

 

  1. magnesium and silver nitrate react to form magnesium nitrate and silver

Mg     +     2AgNO3     Arrow-2.png     Mg(NO3)2     +     2Ag

 

 

  1. silicon tetrachloride produces silicon and chlorine gas

SiCl4     Arrow-2.png     Si     +     2Cl2

 

 

  1. sodium sulfite and calcium chloride yield calcium sulfite and sodium chloride

Na2SO3     +     CaCl2     Arrow-2.png     CaSO3     +     2NaCl

 

 

  1. diphosphorus pentoxide and barium oxide make barium phosphate

P2O5     +     3BaO     Arrow-2.png     Ba3(PO4)2

 

 

  1. calcium and water react to form calcium hydroxide and hydrogen gas

Ca     +     2H2O     Arrow-2.png     Ca(OH)2     +     H2

 

 

  1. iron II oxide and hydrogen chloride make iron II chloride and hydrogen hydroxide

FeO     +     2HCl     Arrow-2.png     FeCl2     +     HOH (or H2O)

 

 

  1. ammonium chloride and barium hydroxide produce ammonium hydroxide and barium chloride

2NH4Cl     +     Ba(OH)2     Arrow-2.png     2NH4OH     +     BaCl2

 

 

  1. potassium nitrate produces potassium nitrite and oxygen

2KNO3     Arrow-2.png     2KNO2     +     O2

 

 

  1. nitrogen monoxide and oxygen combine to form nitrogen dioxide

2NO     +     O2     Arrow-2.png     2NO2

 

 

  1. copper and oxygen make copper II oxide

2Cu     +     O2     Arrow-2.png     2CuO

 

 

  1. iron III hydroxide produces iron III oxide and water

2Fe(OH)3     Arrow-2.png     Fe2O3     +     3H2O

 

 

  1. calcium oxide and sulfur dioxide make calcium sulfite

CaO     +     SO2     Arrow-2.png     CaSO3     (Already balanced)

 

 

  1. magnesium and hydrogen nitrate react to produce magnesium nitrate and hydrogen gas

Mg     +     2HNO3     Arrow-2.png     Mg(NO3)2     +     H2

 

 

  1. zinc carbonate produces zinc oxide and carbon dioxide

ZnCO3    Arrow-2.png     ZnO     +     CO2     (Already balanced)

 

 

  1. calcium sulfate and sodium carbonate make calcium carbonate and sodium sulfate

CaSO4     +     Na2CO3     Arrow-2.png     CaCO3     +     Na2SO4     (Already balanced)