Answer
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: $2.26\times10^{25}\ atoms$
Work Step by Step
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: $7.52\times10^{24}\ molecules\times3 atoms/molecule=2.26\times10^{25}\ atoms$
