How many formula units of nano3 are in 5.23 moles of nano3 (mw. 85.00 g/mol)?

                  3.14 × 10²⁴ Formula Units

                     As we know that 1 mole of any substance contains exactly 6.022 × 10²³ particles which is also called as Avogadro's Number. So in order to calculate the number of particles (formula units) contained by 5.23 moles of NaNO₃, we will use following relation,

           Moles  =  Number of F. Units ÷ 6.022 × 10²³ F. Units.mol⁻¹

Solving for Number of F. Units,

           Number of F. Units  =  Moles × 6.022 × 10²³ F. Units.mol⁻¹

Putting values,

           Number of F. Units  =  5.23 mol × 6.022 × 10²³ Molecules.mol⁻¹

           Number of F. Units  =  3.14 × 10²⁴ F. Units

Hence,

           There are 3.14 × 10²⁴ Formula Units present in 5.23 moles of NaNO₃.

the answer is c. nacl