Part 2: Combustion and Single Displacement Reactions Chemical Reactions Part 2: Combustion and Single Displacement Reactions

Objectives -To identify combustion and single displacement chemical reactions -To predict the products of these two types of reactions

Combustion Reactions Combustion = add oxygen Combustion reactions-most compounds combine with oxygen when they burn to form oxides Key: 1 compound plus oxygen AB + O2  oxide of A + oxide of B 2 C2H6 + 7 O2  4 CO2 + 6 H2O

Combustion Reactions Normally, a compound composed of only C, H, (and maybe O) is reacted with oxygen – usually called “burning” If the combustion is complete, the products will be CO2 and H2O If the combustion is incomplete, the products will be CO (or possibly just C) and H2O

Single Displacement Reactions Single displacement reactions-one element replaces another in a compound More active metals replace less active metals OR More active nonmetals replace less active nonmetals (see activity chart reference) Key: reactants are 1 element and 1 compound (the element can’t be O2)

The “Activity Series” of Metals Lithium Potassium Calcium Sodium Magnesium Aluminum Zinc Chromium Iron Nickel Lead Hydrogen Bismuth Copper Mercury Silver Platinum Gold Higher activity Metals can replace other metals, provided they are above the metal they are trying to replace (i.e. zinc will replace lead) Metals above hydrogen can replace hydrogen in acids Metals from magnesium upward can replace hydrogen in water Lower activity

The “Activity Series” of Halogens Higher Activity Fluorine Chlorine Bromine Iodine Halogens can replace other halogens in compounds, provided they are above the halogen they are trying to replace. Lower Activity 2NaCl(s) + F2(g)  2NaF(s) + Cl2(g) ??? MgCl2(s) + Br2(g)  ??? No Reaction!

Single Displacement Reactions A. More active metals replace less active metals from their compounds (Hydrogen can act like a metal) Cu + 2 AgNO3  Cu(NO3)2 + 2 Ag Zn + H2SO4  ZnSO4 + H2

Single Displacement Reactions B. More active nonmetals replace less active nonmetals from their compounds Cl2 + 2 NaI  2 NaCl + I2

Single Displacement Reactions C. Very active metals (only the first 5) can replace one (AND ONLY ONE) of the hydrogens from the stable compound water. 2 Na + 2 H2O  2 NaOH + H2 a metal hydroxide is always one of the products

Objectives -To identify combustion and single displacement chemical reactions -To predict the products of these two types of reactions