Types of Chemical Reactions Learning Goal I will learn how to represent synthesis, decomposition and displacement chemical reactions using a variety of formats. How are they useful? How do we represent them? What are synthesis, decomposition and displacement reactions? SNC2D1 - 2011 Mr. Findlay

Review Chemical reactions happen all the time and can be very useful We summarize reactions by writing __________ ____________ H2 + O2  H2O chemical equations Reactant(s) Product(s)

Review __________: The finishing chemicals in a reaction (the chemicals produced) ___________: The starting chemicals in a reaction Products Reactants

Examples carbon dioxide water vapour + gasoline + oxygen   CO2(g) + Gasoline burns in air (oxygen) and produces carbon dioxide and water vapour Word Equation Chemical Equation carbon dioxide water vapour + gasoline + oxygen   CO2(g) + H2O (g) C8H18 + O2(g)

Examples Drano clears a drain when the sodium hydroxide and aluminum react with the water to create aluminum hydroxide, hydrogen and sodium ions Word Equation Chemical Equation sodium ions aluminum hydroxide sodium hydroxide + hydrogen + + aluminum + water  + +  Al(OH)3 + H2(g) Na+ NaOH + Al(s) H2O(l)

Synthesis & Decomposition Types of Reactions Synthesis & Decomposition

Synthesis – Putting Things Together Example: sodium + chlorine  sodium chloride 2 Na + Cl2  2NaCl _______ reactants but ______ product Predict the Product: sodium + flourine  _____________________ Products Reactants Many one sodium fluoride

Decomposition – Taking Things Apart Example: water  hydrogen gas + oxygen gas H2O(l)  H2 (g) + O2 (g) _______ reactant but ______ products. Predict the Product: beryllium fluoride  __________ + _________ One many beryllium fluorine

Single Displacement Single displacement reactions have ____ reactants and ___ products. One of the reactants is an element (A), one is a compound (BC). The single element (A) switches places with, or displaces, an element in the compound. 2 2

Single Displacement Video The reaction between aluminum and iron(III) oxide releases so much heat that it can weld steel rails together. aluminum + iron(III) oxide  aluminum oxide + iron 2 Al + Fe2O3  Al2O3 + 2 Fe Video

Double Displacement Double displacement involves two compounds as reactants that produces two other compounds. Ions in the reactants trade places to form new compounds.

Double Displacement The reaction of silver nitrate and sodium chloride produces a white precipitate. silver nitrate + sodium chloride  silver chloride + sodium nitrate AgNO3 (aq) + NaCl (aq)  AgCl(s) + NaNO3(aq) Aqueous solutions (aq) are clear mixtures of substances dissolved in water.