Chemical Reactions
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In chemistry, a chemical reaction is a process which leads to the transformation of one set of chemical substances to another.
Writing Balanced Chemical Equations
All balanced chemical equations have the following features:- mass must be conserved- same number and types of atoms on both sides of the equation- formula subscripts must not be changed- final balanced equation can contain whole number or fraction coefficients
The Law of Conservation of Mass
MASS IS NEITHER CREATED NOR DESTROYED IN ANY ORDINARY CHEMICAL REACTION BECAUSE ATOMS ARE NOT CREATED NOR DESTROYED IN ANY ORDINARY CHEMICAL REACTION
Formation or Single Replacement
element +element --> Compound
Single Decomposition
Compound--> element + element
Single Decomposition
Compound--> element + element
Single Replacement
Element + compound --> element + compound
Cu (s) + 2 AgNO3 (aq) --> 2 Ag (s) + Cu(NO3)2 (aq)
Double Replacement
Compound + compound --> compound + compound
2 NaI (aq) + Pb (NO3)2 (aq) --> PbI2 (s) + 2NaNO3 (aq)
Combustion
compound + O2 (g) --> most common oxides of elements of the compound
Note: most of the time your combustion reaction will be hydrocarbon combustions (involving compounds of the formula CxHy). The format now becomes hydrocarbon + oxygen --> carbon dioxide + water vapour
C3H8 (g) + 5 O2 --> 3CO2 (g) + 4 H2O (g)
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