The process by which one or more substances are changed into one or more different substances...
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Transcript of The process by which one or more substances are changed into one or more different substances...
The process by which one or more substances are changed into one or
more different substances
CHEMICAL REACTIONS
Word EquationsTo write a word equation,
1. Write the names of the reactants to the left of the arrow separated by plus signs;
2. Write the names of the products to the right of the arrow, also separated by plus signs.
Reactant + Reactant Product + Product
Skeleton EquationsWrite the formulas of the reactants to the
left of the yields sign (arrow) and the formulas of the products to the right.
A skeleton equation is a chemical equation that does not indicate the relative amounts of the reactants and products.Here is the equation for rusting:Fe + O2 Fe2O3
CatalystA catalyst is a substance that speeds up
the reaction but is not used up in the reaction
Without catalyst With Catalyst
Balancing Chemical Equations
To write a balanced chemical equation,1.Write the skeleton equation2.Use coefficients to balance the equation so that
it obeys the law of conservation of mass. Remember you want the same number of
atoms of each element on each side of the equation.
Example 3 -- Try on your own!!!Write a balanced chemical equation for the
reaction in which sodium hydroxide and calcium bromide react to produce solid calcium hydroxide and sodium bromide. (The reaction occurs in water.)
NaOH(aq)+CaBr2(aq) Ca(OH)2(s)+NaBr(aq)
2NaOH(aq)+CaBr2(aq) Ca(OH)2(s)+2NaBr(aq)
Chemical Equations from Names
Magnesium and Hydrogen Chloride produce Hydrogen and Magnesium Chloride
Calcium Hydroxide and Lithium Chloride produce Lithium Hydroxide and Calcium Chloride
Decompose Copper (II) oxide into Copper and Oxygen
Aluminum and Iron (III) oxide produce iron and aluminum oxide
combustion of Butane (C4H10) in air to produce carbon dioxide and water
1. Synthesis Reactions (Combination)
Two or more reactants produce one product
Examples:NH3 + HCl NH4Cl
H2 + O2 H2O
Ag + S Ag2S
Al + Cl2 AlCl3
2. DecompositionOne reactant produces
two or more productsExamples
Ag2O Ag + O2
PCl5 PCl3 +Cl2
H2O2 H2O + O2
CuO Cu + O2
3. Single Replacement
One element and one compound producing a different element and compound
ExamplesFe + H3(PO4) H2 + Fe3(PO4)2
H2 + CuO Cu + H2O
Zn + HCl H2 + ZnCl2
Cl2 + KBr Br2 + KCl
4. Double Replacement
A double-replacement reaction is a chemical change involving an exchange of positive ions between two compounds.
Examples:
Al(NO3)3 + NaOH Al(OH)3 + NaNO3
PbCl2 + Li2SO4 PbSO4 + LiCl
ZnBr2 + AgNO3 Zn(NO3)2 + AgBr
BaCl2 + KIO3 Ba(IO3)2 + KCl
4. Double replacementThree main products of a double
replacement reaction Precipitate (solubility table)WaterGas
5. Combustion A combustion reaction
Chemical changeElement or a compound reacts with oxygen Producing energy in the form of heat and
light