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Warm-up. Write the formula for each of the following: Sodium sulfide Potassium phosphate Aluminum oxide Stannous flouride. Chemical Equation- represents, with symbols and formulas, the identities and relative amounts of the reactants and products in a chemical reaction.
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Warm-up Write the formula for each of the following: Sodium sulfide Potassium phosphate Aluminum oxide Stannous flouride
Chemical Equation- represents, with symbols and formulas, the identities and relative amounts of the reactants and products in a chemical reaction. 2Na + Cl2 2NaCl Reactants “yields” Products
Symbols you’ll see in equations! (s), (l), (g), and (aq) D
Words to chemical equation Solid sodium hydroxide and aqueous hydrochloric acid produces aqueous sodium chloride and liquid water aqueous silver nitrate and aqueous potassium bromide produces solid silver bromide and aqueous potassium nitrate
Characteristics of a Chemical Equation • Must represent known facts • Must contain correct formulas • Must satisfy The Law of Conservation of Mass
How to satisfy Law of Conservation of Mass (Balancing the Equation) • To equalize numbers of atoms, use coefficients (appears in front of formula) DO NOT CHANGE SUBSCRIPTS!
Balancing Steps 1. Write the unbalanced equation. • Count atoms on each side. • Find least common multiple of the each atom 4. Add coefficients to make #s equal. Coefficient subscript = # of atoms 5. Double check the atom balance!!!
Helpful Tips • Balance one element at a time. • Update ALL atom counts after adding a coefficient. • If an element appears more than once per side, balance it last. • Balance polyatomic ions as single units. • “1 SO4” instead of “1 S” and “4 O”
In Class Problems:Balance each • KClO3 KCl + O2 • Mg(NO3)2 + KOH Mg(OH)2 + KNO3 • Pb(NO3)2 + NaOH NaNO3 + Pb(OH)2 • P4O10 + H2O H3PO4 • Li + O2 Li2O • Al + NiSO4 Ni + Al2(SO4)3 • ZnS + O2 ZnO + SO2