Balancing Chemical Equations

Standards SC2. Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions. SC2a Identify and balance the following types of chemical equations: • Synthesis • Decomposition • Single Replacement • Double Replacement • Combustion

Law of Conservation of Mass In ordinary chemical reactions, the total mass of reacting substances is equal to the total mass of products All atoms on the reactant side must appear on the product side, and in equal numbers No new elements may appear No elements may disappear

Types of Chemical Equations Synthesis Reaction A + X  AX one product Decomposition Reaction AX  A + X one reactant Single Replacement Reaction A + BX  B +AX one element replaces another in a compound Double Replacement Reaction AX + BY  AY + BX elements in a compound switch partners Combustion Reaction AB + O2  AO + BO Compound burns in oxygen gas Acid Base (Neutralization)Reaction HA + XOH  XA + H2O acid and base react to form a salt and water

Synthesis Reactions 1. ___CaO + ___H2O  ___Ca(OH)2 2. ___P4 + ___O2  ___P2O5 3. ___Ca + ___O2  ___CaO 4. ___Cu + ___S8  ___ CuS 5. ___CuO + ___H2O  ___Cu(OH)2 6. ___S8 + ___O2  ___SO2 7. ___H2 + ___N2  ___NH3 8. ___H2 + ___Cl2  ___HCl 9. ___Ag + ___S8  ___Ag2S 10. ___Cr + ___O2  ___Cr2O3

Decomposition Reactions 11. ___BaCO3  ___BaO + ___CO2 12. ___MgCO3  ___MgO + ___CO2 13. ___K2CO3  ___K2O + ___CO2 14. ___Zn(OH)2  ___ZnO + ___H2O 15. ___Fe(OH)2  ___FeO + ___H2O 16. ___Ni(ClO3)2  ___NiCl2 + ___O2 17. ___NaClO3  ___NaCl + ___O2 18. ___KClO3  ___KCl + ___O2 19. ___H2SO4  ___H2O + ___SO3 ___H2CO3  ___H2O + ___CO2

Single Replacement Reactions 21. ___AgNO3 + ___Ni  ___Ni(NO3)2 + ___Ag 22. ___AlBr3 + ___Cl2  ___AlCl3 + ___Br2 23. ___NaI + ___Br2  ___NaBr + ___I2 24. ___Ca + ___HCl  ___CaCl2 + ___H2 25. ___Mg + ___HNO3  ___Mg(NO3)2 + ___H2 26. ___ Zn + ___H2SO4  ___ZnSO4 + ___H2 27. ___K + ___H2O  ___KOH + ___H2 28. ___Na + ___H2O  ___NaOH + ___H2

Double Replacement Reactions 29. ___AlI3 + ___HgCl2  ____AlCl3 + ____HgI2(ppt) 30. ___HCl + ___NaOH  ___NaCl + ___H2O 31. ___BaCl2 + ___H2SO4  ___BaSO4 + ___HCl 32. ___Al2(SO4)3 + ___Ca(OH)2  ___Al(OH)3 + ___CaSO4 33. ___AgNO3 + ___K3PO4  ___Ag3PO4 + ___KNO3 34. ___CuBr2 + ___AlCl3  ___CuCl2 + ___AlBr3 35. ___Ca(C2H3O2)2 + ___Na2CO3  ___CaCO3 + ___NaC2H3O2 36. ___NH4Cl + ___Hg2(C2H3O2)2  ___NH4 C2H3O2 + ___Hg2Cl2 37. ___Ca(NO3)2 + ___HCl  ___CaCl2 + ___HNO3 38. ___FeS + ___HCl  ___FeCl2 + ___H2S

Combustion Reactions 39. ___C2H6 + ___O2  ___CO2 + ___H2O 40. ___C3H8 + ___O2  ___CO2 + ___H2O 41. ___C4H10 + ___O2  ___CO2 + ___H2O 42. ___C5H12 + ___O2  ___CO2 + ___H2O 43. ___C6H14 + ___O2  ___CO2 + ___H2O 44. ___C2H4 + ___O2  ___CO2 + ___H2O 45. ___C2H2 + ___O2  ___CO2 + ___H2O 46. ___C6H6 + ___O2  ___CO2 + ___H2O

Acid Base (Neutralization)Reactions ___HCl+ ___ NaOH  ___ H2O + ___ NaCl ___ HF + ___ LiOH  ___ H2O + ___ LiF ___ H3PO4 + ___ LiOH  ___ H2O + ___ Li3PO4 ___ Fe(OH)3 + ___ HNO3  ___ Fe(NO3) 3 + ___ H2O