Question

Calculate the number of sodium ions, perchlorate ions, Cl atoms, and O atoms in 1.42 g of sodium perchlorate. Enter your answers in scientific notation.

Answer 1

Find moles of NaClO4:

$$n(NaClO_4)=\frac{m}{M}=\frac{1.42}{122.44}=0.0116 mol$$

As one formula unit contains one sodium ion then n(Na⁺) =n(NaClO₄) = 0.0116 mol

$$N=N_A\times n$$

$N(Na^+)=0.0116\times 6.022\times 10^{23}=6.99\times10^{21} ions$

As one formula unit contains one perchlorate ion then n(ClO₄^-) =n(NaClO4) = 0.0116 mol

$N(ClO_4^-)=0.0116\times 6.022\times10^{23} =6.99\times10^{21} ions$

As one formula unit contains one atom of chlorine then n(Cl) =n(NaClO4) = 0.0116 mol

$N(Cl) = 0.0116\times 6.022\times 10^{23} = 6.99\times10^{21} atoms$

As one formula unit contains 4 atoms of oxygen then n(O) =4*n(NaClO4) = 4*0.0116 mol=0.0464 mol

$N(O) = 0.0464\times 6.022\times10^{23} =2.79\times10^{22} atoms$