Presentation on theme: "Types of Chemical Reactions Special Cases of Synthesis & Decomposition"— Presentation transcript:
1 Types of Chemical Reactions Special Cases of Synthesis & Decomposition We know the basics, but how about the specifics?
2 Special Types of Synthesis Reactions Metals Metal + Oxygen → Metal oxide4Na(s) + O2(g) → 2Na2O(s)2Mg(s) + O2(g) → 2MgO(s)Metal + Sulfur → Metal SulfideWhy the same?Metal Oxide + Water → Metal HydroxideNa2O(s) + H2O(l) → 2NaOH(aq)MgO(s) + H2O(l) → Mg(OH)2(aq)
3 Special Types of Synthesis Reactions Nonmetals Non-metals will react with oxygen to form non-metal oxides:S8(s) + 8O2(g) → 8SO2(g)C(s) + O2(g) → CO2(g)Non-metals will also react with Cl2 or Br2 to form chlorides or bromidesP4(s) + 6 Br2(l) → 4 PBr3(l)Non-metal oxides react with water to form oxyacids:SO2(g) + H2O(l) → H2SO3(aq)
4 Reactions of Metals with Halogens Mg(s) + Cl2(g) → MgCl2(s)This referred to as an oxidation-reduction (REDOX) reactionWhy?Magnesium is oxidized (electrons are lost)Chlorine is reduced (electrons are gained)Cl2 causes Mg to be oxidized and is called the oxidizing agentMg causes Cl2 to be reduced and is the reducing agent
5 Decomposition Reactions of Metals Metal Carbonates (+ heat) → Metal Oxide + CO2(g)CaCO3 → CaO(s) + CO2(g)Metal Hydroxides (+ heat) → Metal Oxide + H2O(l)Ca(OH)2 → CaO + H2ODoes not happen for Group I hydroxides
6 Decomposition Reactions of Metals Metal Chlorates (+ heat) → Metal Chloride + O2(g)2 KClO3(s) → 2 KCl(s) + 3 O2(g)This reaction takes place with a catalyst (a substance added to speed up reaction that is not changed)Metal Nitrates (+ heat) → Metal Nitrite + O2(g)2 NaNO3 → 2 NaNO2 + O2(g)Hydrogen Peroxide (+ catalyst) → H2O(l) + O2(g)