Predicting Chemical Reactions

Activity Series Activity Series is an order of elements organized according to the ability for the elements to undergo a chemical reaction. (Hierarchical list) Metals on the list: likely to lose an electron Nonmetals on the list: likely to gain an electron Just because a chemical reaction is written does not mean that it will take actually happen.

Activity Series

Synthesis Remember: Synthesis Reactions describe a chemical reaction in which two or more substances for a new compound. Most commonly found with an element reacting with oxygen (O2) or sulfur (S8).

Synthesis: Oxygen & Sulfur Consider the charges to determine name of compound. When a metal reacts with oxygen it produces an oxide. Fe + O2  FeO : Iron (II) Oxide Fe + 02  Fe2O3 : Iron (III) Oxide When a metal reacts with sulfur it produces a sulfide. Ba + S8  BaS

Synthesis: Metals with Halogens Depends on the charge of the metal. Na + Cl2  NaCl Mg + F2  MgF2 CO + F2  CoF3

Synthesis: Oxides Metals: CaO + H2O  Ca(OH)2 Nonmetals: React with water to produce a metal hydroxide. CaO + H2O  Ca(OH)2 Nonmetals: React with water to produce oxyacids. SO2 + H2O  H2SO3

Decomposition Remember: Decomposition Reactions describes a chemical reaction in which one compound becomes two simpler substances. Most commonly found as an endothermic reaction.

Decomposition: Binary Compounds Binary Compound has two different types of elements bonded together. Oxides of the less-active metals (located lower center on the periodic table), decompose into their elements when heated. Hg0  Hg + O2

Decomposition: Metal Carbonates Metal carbonate breaks down into a metal oxide and carbon dioxide. CaCO3  CaO + CO2

Decomposition: Metal Hydroxides Metal hydroxides decompose into metal oxide and water. Except if the metal is found in Group 1. Ca(OH)2  CaO + H2O

Decomposition: Metal Chlorates After being heated, metal chlorates decompose into metal chloride and oxygen. KClO3  2KCl + O2

Decomposition: Acids Decompose into metal oxides and water. H2CO3  CO2 + H2O H2SO4  SO3 + H2O

Single-Displacement Remember: Single displacement describes a reaction which one element replaces a similar element in a compound. Most single replacement reactions take place within an aqueous solution.

Single-Displacement: Metal displaced by a Metal Reaction will take place if activity of single metal is higher than that within the compound. Al + Pb(NO3)2  Pb + Al(NO3)3

Single-Displacement: H in H20 displaced by a Metal Higher active metals react with water in liquid state to form hydroxides and hydrogen gas. Na + H20 (l)  NaOH + H2 Lower active metals require energy input for water to be steam in order to produce a metal oxide and hydrogen gas. Fe + H20 (g)  Fe2O3 + H2

Single-Displacement: H in acid displaced by a Metal Higher active metals react with certain acidic solutions. The reaction produces an ionic compound and hydrogen gas. Mg + HCl  MgCl2 + H2

Single-Displacement: Halogens displaced by Halogens Higher active halogens (non-metals in group17) may displace a lower active halogen. F2 + 2NaCl  Cl2 + NaF Remember, each halogen element has lower activity than the one above it. Usually is displaced in an ionic compound, producing a new ionic compound.

Double-Displacement Remember: Single displacement describes a reaction which two ions exchange places to form new compounds. The reaction produces a precipitate, an insoluble gas (bubbles out), or a molecular compound (typically water).

Solubility Chart

Predicting the Products of a Double Replacement Reaction Given the reactants, write the name of the products by switching the LAST names Do not use acid names; use FULL NAME ex: Don’t use Nitrous Acid; use Hydrogen Nitrite Check the Table of Solubility Rules If something is insoluble  it will form a precipitate (s) during the rxn RXN WILL OCCUR If a liquid/ gas has formed If something is soluble  it will form an aqueous (aq) product (If you finish with 2 soluble (aq) reactants) NO RXN (stop there)

The Exceptions! 5 things that may seem soluble, but will actually produce a liquid or a gas  a reaction WILL occur If any of these are a product, there will be a rxn Hydrogen Carbonate  breaks into water and Carbon Dioxide H2CO3 (aq)  H2O (l) + SO2 (g) if you make Hydrogen Carbonate, the CO2 bubbles (gas) produced = rxn Hydrogen Sulfite  breaks into water and Sulfur Dioxide H2SO3 (aq)  H2O (l) + SO2 (g) Ammonium Nitrate  breaks into water and Ammonia NH4OH (aq)  H2O (l) + NH3 (g)

Exceptions (cont.) Hydrogen Sulfide - H2S Hydrogen Hydroxide – HOH Odor produced (rotten eggs) Hydrogen Hydroxide – HOH Water H2O (l) (which is a rxn)