## Chemistry and Chemical Reactivity (9th Edition)

Number of moles: $12.5\ mol$ Number of molecules: $7.52\times10^{24}\ molecules$ Number of S atoms: $7.52\times10^{24}\ atoms$ Number of O atoms: $2.26\times10^{25}\ atoms$
Atomic weights: $S: 32.06u,\ O: 15.999u$ Molar mass: $32.06+3\times15.999=80.057\ g/mol$ Total mass: $1.00\ kg \times 10^3\ g/kg= 1.00\times10^3\ g$ Number of moles: $1.00\times10^3\ g\div80.057\ g/mol=12.5\ mol$ Number of molecules: $12.5\ mol\times6.022\times10^{23}molecules/mol = 7.52\times10^{24}\ molecules$ Number of S atoms: $7.52\times10^{24}\ molecules\times1 atom/molecule=7.52\times10^{24}\ atoms$ Number of O atoms: $7.52\times10^{24}\ molecules\times3 atoms/molecule=2.26\times10^{25}\ atoms$