## Chemistry and Chemical Reactivity (9th Edition)

a) Number of moles of nickel (II) acetate: $0.500\ g\div 176.78\ g/mol=2.83\times10^{-3}\ mol$ From stoichiometry, same number of moles of nickel (II) formate. $2.83\times10^{-3}\ mol\times 148.72\ g/mol=0.42\ g$ b) Nickel (II) is paramagnetic since it has two unpaired electrons ($[Ar]\ 3d^8$). c) Number of moles of nickel (II) formate: $0.253\ g\div 148.72\ g/mol=1.70\times10^{-3}\ mol$, same as nickel metal. $1.70\times10^{-3}\ mol\times 58.693\ g/mol=0.10\ g$ Nickel atoms are paramagnetic with two unpaired electrons ($[Ar]\ 3d^8\ 4s^2$).