Chapter 8 Lecture Basic Chemistry Fourth Edition Chapter 8 Chemical Reactions 8.3 Types of Reactions Learning Goal Identify a reaction as a combination, decomposition, single replacement, double replacement, or combustion. © 2014 Pearson Education, Inc. In a combination reaction, two or more substances combine to form one substance as the product.

© 2014 Pearson Education, Inc. Types of Reactions Chemical reactions may be classified as combination decomposition single replacement double replacement combustion

© 2014 Pearson Education, Inc. Combination Reactions In a combination reaction, two or more elements form one product two or more simple compounds combine to form one product 2Mg(s) + O 2 (g)  2MgO(s) N 2 (g) + 3H 2 (g)  NH 3 (g)

© 2014 Pearson Education, Inc. Combination Reactions In a combination reaction, two or more substances combine to form one substance as the product.

© 2014 Pearson Education, Inc. Decomposition Reactions In a decomposition reaction, one reactant splits into two or more simpler substances

© 2014 Pearson Education, Inc. Decomposition Reactions In a decomposition reaction, one reactant breaks down into two or more products.

© 2014 Pearson Education, Inc. Chemistry Link to Health Photochemical smog is prevalent in cities that depend on cars for transportation is formed when nitrogen oxide (NO) emissions from cars combine with oxygen gas to form nitrogen dioxide 2NO(g) + O 2 (g)  2NO 2 (g)

© 2014 Pearson Education, Inc. Chemistry Link to Health Nitrogen dioxide (NO 2 ) gas is a reddish-brown gas that irritates eyes and is damaging to lungs reacts in the presence of sunlight to form NO molecules and O atoms NO 2 (g)  NO(g) + O(g) oxygen atoms

© 2014 Pearson Education, Inc. Chemistry Link to Health The reddish-brown color of smog is due to nitrogen dioxide.

© 2014 Pearson Education, Inc. Chemistry Link to Health Single oxygen atoms are very reactive and combine with molecules in the atmosphere to form ozone. O(g) + O 2 (g)  O 3 (g) Ozone In the lower atmosphere, ozone irritates the eyes and respiratory tract damages fabric and rubber as well as trees and crops

© 2014 Pearson Education, Inc. Single-Replacement Reactions In a single-replacement reaction, an uncombined element replaces an element in a compound. Zn(s) + 2HCl(aq)  ZnCl 2 (aq) + H 2 (g) Fe(s) + CuSO 4 (aq)  FeSO 4 (aq) + Cu(s)

© 2014 Pearson Education, Inc. Single-Replacement Reactions In a single replacement reaction, an atom or ion replaces an atom or ion in a compound.

© 2014 Pearson Education, Inc. Double-Replacement Reactions In a double-replacement reaction, two elements in the reactants exchange places. AgNO 3 (aq) + NaCl(aq)  AgCl(s) + NaNO 3 (aq) NaOH(aq) + HCl(aq)  NaCl(aq) + HOH(l)

© 2014 Pearson Education, Inc. Double-Replacement Reactions In a double replacement reaction, the positive ions in the reactants replace each other.

© 2014 Pearson Education, Inc. Combustion Reactions In a combustion reaction, carbon containing compounds, fuel burns in oxygen from the air to produce carbon dioxide, CO2, water, H2O, and heat or flame.

© 2014 Pearson Education, Inc. Combustion Reactions Butane, an alkane with 4 C atoms and 10 H atoms, is used as a fuel for a camp stove.

© 2014 Pearson Education, Inc. Summary of Reaction Types

© 2014 Pearson Education, Inc. Learning Check Identify each type of reaction as (C) combination (D) decomposition (SR) single replacement (DR) double replacement 3Ba(s) + N 2 (g)  Ba 3 N 2 (s) 2Ag(s) + H 2 S(aq)  Ag 2 S(s) + H 2 (g) SiO 2 (s) + 4HF(aq)  SiF 4 (s) + 2H 2 O(l) K 2 CO 3 (s)  K 2 O(aq) + CO 2 (g)

© 2014 Pearson Education, Inc. Solution Identify each type of reaction as (C) combination (D) decomposition (SR) single replacement (DR) double replacement C3Ba(s) + N 2 (g)  Ba 3 N 2 (s) SR2Ag(s) + H 2 S(aq)  Ag 2 S(s) + H 2 (g) DRSiO 2 (s) + 4HF(aq)  SiF 4 (s) + 2H 2 O(l) DK 2 CO 3 (s)  K 2 O(aq) + CO 2 (g)