Chemical Reactions

Warm Up What is the mass of this object, with the appropriate number of significant figures.

What Makes a Reaction Chemical? Atoms are rearranged to form a new substance Evidence of a chemical reaction: Heat Emitting Absorbing Light Color change Odor Gas bubbles Formation of a solid

Terminology Reactant: starting substances Product: substances produced during the reaction Symbols: + Separates two or more reactants or products → Represents the reaction, separates the reactants and products Represents a reversible reaction, separates the reactants and products (s) Solid state (l) Liquid state (g) Gaseous state (aq) Water (aqueous) solution

Writing Chemical Reaction Equations Reactant 1 + Reactant 2 → Product 1 + Product 2

Word Equations Write a word equation that describes the reaction between Aluminum and Bromine Determine phase of each element: Aluminum is a solid (s) Bromine is a liquid (l) Write word equation: Aluminum (s) + bromine (l) → aluminum bromide (s) Reads as: Aluminum and Bromine react to produce aluminum bromide

Skeleton Equations Replace element names with chemical symbols Indicate the number of atoms in the products Determine the chemical symbols for reactants Solid Aluminum = Al (s) Liquid Bromine = Br2 (l) Calculate chemical formula for products Figure out ionization state for each element Al +3 Br-1 Criss Cross charges to find number of atoms of each element Al1BR3 AlBr3 Replace words with chemical formulas Al (s) + Br2 (l) → AlBr3 (s)

Practice Write a word equation and then skeleton equation for the following reactions: Hydrogen and Bromine gas react to form hydrogen bromide Carbon monoxide and oxygen react to form carbon dioxide

Types of Chemical Reactions Aluminum & CuCl2 by Mr. W

/Synthesis/ The get-together

/Synthesis/ The get-together Two or more chemicals bond together forming one new substance.

/Synthesis/ The get-together A + B  AB

/Synthesis/ The get-together 2Na + Cl2  2NaCl

/Decomposition/ The break-up

/Decomposition/ The break-up One substance breaks down into two or more separate substances.

/Decomposition/ The break-up AB  A + B

/Decomposition/ The break-up 2H2O2  2H2O + O2

/Single Replacement/ The cheater

/Single Replacement/ The cheater One element knocks another element out of a compound.

/Single Replacement/ The cheater AB + X  AX + B

/Single Replacement/ The cheater 2HCl + Zn  ZnCl2 + H2

/Double Replacement/ The swap

/Double Replacement/ The swap Two compounds switch ions with each other.

/Double Replacement/ The swap AB + XY  AX + BY

/Double Replacement/ The swap BaCl2 + Na2SO4  BaSO4 + 2NaCl

/Combustion/ Everyone loves O2

/Combustion/ Everyone loves O2 A compound burns in oxygen gas.

/Combustion/ A + O2 Everyone loves O2 Oxygen will always be a reactant. A + O2

/Combustion/ Everyone loves O2 2Mg + O2  2MgO

Clicker Quiz Questions For each reaction, select the type of reaction from the types that we just learned. Options: Decomposition Synthesis Singe Displacement Double Displacement Combustion

Question 1 2H2 + O2 -> 2H2O Decomposition Synthesis Singe Displacement Double Displacement Combustion B

Question 2 2KClO3 -> 2KCl + 3O2 Decomposition Synthesis Singe Displacement Double Displacement Combustion A

Question 3 Zn + 2HCl -> H2 + ZnCl2 Decomposition Synthesis Singe Displacement Double Displacement Combustion C

Question 4 2S + 3O2 -> 2SO3 Decomposition Synthesis Singe Displacement Double Displacement Combustion e

H2SO4 + 2NaOH -> Na2SO4 + 2H2O Question 5 H2SO4 + 2NaOH -> Na2SO4 + 2H2O Decomposition Synthesis Singe Displacement Double Displacement Combustion D

Question 6 Ca(OH)2 -> CaO + H2O Decomposition Synthesis Singe Displacement Double Displacement Combustion A

Question 7 H2 + 2AgNO3 -> 2Ag + 2HNO3 Decomposition Synthesis Singe Displacement Double Displacement Combustion c

Question 8 C10H8 + 12O2 -> 10CO2 + 4H2O Decomposition Synthesis Singe Displacement Double Displacement Combustion E

Question 9 2Li2S + 2Cl2 -> 4LiCl + S2 Decomposition Synthesis Singe Displacement Double Displacement Combustion B

Question 10 2Fe + 6NaBr -> 2FeBr3 + 6Na Decomposition Synthesis Single Displacement Double Displacement Combustion C

Question 11 CH4 + 2O2 -> Co2 +2H2O Decomposition Synthesis Single Displacement Double Displacement Combustion E

NaOH + KNO3 -> NaNO3 + KOH Question 12 NaOH + KNO3 -> NaNO3 + KOH Decomposition Synthesis Single Displacement Double Displacement Combustion D

CaSO4 + Mg(OH)2 -> Ca(OH)2 + MgSO4 Question 13 CaSO4 + Mg(OH)2 -> Ca(OH)2 + MgSO4 Decomposition Synthesis Single Displacement Double Displacement Combustion D

Question 14 2KClO3 -> 2KCl + 3O2 Decomposition Synthesis Single Displacement Double Displacement Combustion A

Question 15 Pb + O2 -> PbO2 Decomposition Synthesis Single Displacement Double Displacement Combustion E

Question 16 2Na + 2H2O -> 2NaOH + H2 Decomposition Synthesis Single Displacement Double Displacement Combustion C

Question 17 6CO2 + 6H2O ->C6H12O6 + 6O2 Decomposition Synthesis Single Displacement Double Displacement Combustion B

HCl + NaOH -> NaCl + H2O Question 18 HCl + NaOH -> NaCl + H2O Decomposition Synthesis Single Displacement Double Displacement Combustion D