Chemistry and Chemical Reactivity (9th Edition)

1: Zn is in excess, $7.00\ g\div 65.38\ g/mol=0.107\ mol$ Ratio: $0.100/0.107=0.934\lt2$ 2: Zn is in stoichiometric amount, $3.27\ g\div 65.38\ g/mol=0.050\ mol$ Ratio: $0.100/0.050=2.00=2$ 3: Zn is the limiting reactant, $1.31\ g\div 65.38\ g/mol=0.020\ mol$ Ratio: $0.100/0.020=5.00\gt2$