Predicting Products Chemistry General Chemistry Ch 11 Accelerated Chemistry Ch 3

How to predict the products You have to figure out which type of equation you have Then there are certain characteristics which will help you decide what is formed You must still CROSS CHARGES and use diatomic molecules if needed

Double Replacement Both ions will “switch partners” Metals replace metals; Nonmetals replace nonmetals AB + CD  AD + CB –Needs to have positive part first with a negative part –Needs to have charges crossed NaOH + CaSO 4  Na 2 SO 4 +Ca(OH) 2

Double Replacement Examples Predict the products: NaOH + HCl → CaSO 4 + KBr → Al 2 O 3 + Fe(CN) 3 → AlCl 3 + BaSO 3 → NaCl +HOH CaBr 2 +K 2 SO 4 Al(CN) 3 +Fe 2 O 3 Al 2 (SO 3 ) 3 +BaCl 2

Single Replacement Single element will “cut-in” on its like component in a compound Metals replace metals; Nonmetals replace nonmetals AB + C  AC + B –Positive part still first with negative part –Still have to cross charges for the compound –If the single element is a diatomic... NaF + Cl 2  NaCl +F2F2

Activity Series For Metals –Metals Activity series: Low to high Au, Pt, Hg, Ag, Cu, H 2, Pb, Sn, Ni, Co, Fe, Cr, Zn, Mn, Al, Mg, Na, Ca, Ba, K, Li For Nonmetals –Nonmetals Activity Series: Low to high I 2, Br 2, Cl 2, F 2

Single Replacement Examples Predict the products: Mg + CuO → Au + NaBr → Cl 2 + KBr → I 2 + AlF 3 → Cu +MgO No Reaction Br 2 +KCl No Reaction Au, Pt, Hg, Ag, Cu, H 2, Pb, Sn, Ni, Co, Fe, Cr, Zn, Mn, Al, Mg, Na, Ca, Ba, K, Li I 2, Br 2, Cl 2, F 2

Synthesis All the reactants add up into ONE product It needs to “make sense” Charges may still need to be crossed A + B + C  ABC Mg + O 2  MgO

Decomposition One Reactant breaks down into multiple products Typically into single elements Remember the diatomic molecules DEF  D + E + F AlCl 3  Al +Cl 2

Combustion Very specific products H 2 O and CO 2 Reactants can only be C, H (and sometimes O) and O 2 C 3 H 6 + O 2  H 2 O +CO 2