Balancing Chemical Equations Unit 6 Part B Balancing Chemical Equations ABClark-Grubb

H2 + O2 H2O Step #1 Write the formulas of the reaction Hydrogen + Oxygen     Dihydrogen Monoxide    H2 + O2 H2O

Step #2 Count the number of atoms of each element on 
both sides of the reaction Pull H2 + O2 H2O

THIS IS WRONG Never change the subscripts 
 Would you want to drink a nice cold glass of 
hydrogen peroxide instead of water? H2 + O2 H2O2 =

Step #3 Change the coefficients to make the number of 
atoms equal on both sides Must satisfy the law of conservation of mass, equal number of atoms on each side __H2 + __O2 __H2O

Tips for Balancing Balance the types of atoms that 
appear in only one reactant and 
one product first. Save H atoms and O atoms for last If the same polyatomic ion appears on both sides of the equation, treat it as a single unit.

Example AgNO3 + CaCl2 AgCl + Ca(NO3)2

More Examples Step #1 chlorine + sodium bromide   bromine + sodium chloride Step #1 Cl2 + NaBr Br2 + NaCl

Step #2 & 3 __Cl2 + __NaBr __Br2 + __NaCl

sodium + chlorine   sodium chloride Na Cl2 + NaCl It might help to make a table 
to keep track of what you 
need to balance.

Example + + AgNO3 Cu Cu(NO3)2 Ag silver nitrate + copper  copper(II) nitrate + silver AgNO3 + Cu Cu(NO3)2 + Ag

Try these… Mg + N2  Mg3N2 P + O2  P4O10 CH4 + O2  CO2 + H2O Na + H2O  H2 + NaOH

Try these… Mg + N2  Mg3N2

Try these… P + O2  P4O10

Try these… CH4 + O2  CO2 + H2O

Try these… Na + H2O  H2 + NaOH

Answers 3Mg + N2  Mg3N2 4P + 5O2  P4O10 CH4 + 2O2  CO2 + 2H2O 2Na + 2H2O  H2 + 2NaOH