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What did the chemist yell when she passed a cute guy in her sports car?. Radon, baby!. Balancing Redox Equations. Use the 5 step method! Number of electrons lost must be equal to the number of electrons gained You must balance your equation!. Ag 2 S (s) + Al (s) Al 2 S 3(s) + Ag (s).
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What did the chemist yell when she passed a cute guy in her sports car? Radon, baby!
Balancing Redox Equations • Use the 5 step method! • Number of electrons lost must be equal to the number of electrons gained • You must balance your equation!
Ag2S(s) + Al(s) Al2S3(s) + Ag(s) • Step 1: Determine the oxidation number of each atom in the reaction to identify the atoms whose oxidation numbers have changed Ag2S(s) + Al(s) Al2S3(s) + Ag(s)
Ag2S(s) + Al(s) Al2S3(s) + Ag(s) • Determine the # of electrons transferred per atom/ion from the change in oxidation # • Ag: change in ox. # from +1 to o • ...gain of 1 electron per atom • Al: change in ox # from 0 to +3 • ...loss of 3 electrons per atom
Ag2S(s) + Al(s) Al2S3(s) + Ag(s) • Determine the number of electrons transferred per mole from the subscripts in the chemical formula • Ag2S: 2(1e-) = 2e-/mole • Al: 1(3e-) = 3e-/mole
Ag2S(s) + Al(s) Al2S3(s) + Ag(s) • Make e-’s lost = e-’s gained • Ag2S: 2e-/mole * 3 = 6e- • Al: 3e-/mole * 2 = 6e- • Take the # you multiplied it by and place it in front as the coefficient for that compound 3Ag2S(s) + 2Al(s) Al2S3(s) + Ag(s)
Ag2S(s) + Al(s) Al2S3(s) + Ag(s) • Balance as usual 3Ag2S(s) + 2Al(s) Al2S3(s) + 6Ag(s)