CHEM 1011 Classes of Chemical Reactions Safety Put

CHEM 1011 Classes of Chemical Reactions

Safety Put on Goggles And Apron

Chemical Reaction Reactants → Products • Products’ characteristics and properties differ from reactants’

Four Reaction Types • • Combination Decomposition Single Replacement (Substitution) Double Replacement (Metathesis)

Combination Reactions • Two elements react to form a compound A + B → AB e. g. , 2 Na (s) + Cl 2 (g) → 2 Na. Cl (s)

Decomposition Reactions • Compound breaks down into simpler elements or compounds AB → A + B e. g. , 2 Hg. O (s) → 2 Hg (l) + O 2 (g)

Single Replacement (Substitution) • Replacement of one component in a compound by another AB + C → CB + A e. g, Cu (s) + 2 Ag. NO 3 (aq) → 2 Ag (s) + Cu(NO 3)2 (aq) 2 Mg + CO 2 → 2 Mg. O + C

Activity Series A c t i v i t y

Single Replacement (Substitution) • Refer to Activity Series Chart to dictate substitution • Elements cannot replace anything above them • Cu (s) + Al. Cl 3 (aq) → No Reaction

Single Replacement (Substitution) • Hydrogen can be replaced by a very active metal. e. g. , Zn (s) +2 HCl (aq) → Zn. Cl 2 (aq) + H 2 (g)

Double Replacement Reactions • Two compounds react to form two different compounds AB +CD → AD + CB e. g. , Fe. Cl 3 (aq)+ 3 Na. OH (aq) → 3 Na. Cl (s) + Fe(OH)3 (aq)

Conclusions • Observe energy and physical changes • Balance all equations resulting in a reaction • Make sure to use your activity series chart when determining if reactions occur or not