Answer:
The mass of [tex]Fe^{3+}[/tex] present is [tex]x = 7.2 *10^{4} \ ng[/tex]
Explanation:
From the question we are told that
The diameter of the spot is [tex]d = 1.0 \ cm[/tex]
The volume of the solution present is [tex]v = 12 \mu L = 12 *10^{-6} \ L[/tex]
The mass of [tex]Fe^{3+}[/tex] ions in one liter of solution is [tex]m_f = 6.0 \ g[/tex]
Generally the mass of [tex]Fe^{3+}[/tex] ions present is v is mathematically represented as
[tex]x = \frac{v * m_f}{ 1}[/tex]
[tex]x = \frac{12 *10^{-6} * 6}{1}[/tex]
[tex]x = 7.2*10^{-5} \ g[/tex]
Converting to nanograms
We have
[tex]x = 7.2*10^{-5} \ g = \frac{ 7.2*10^{-5}}{1 *10^{-9}} = 7.2 *10^{4} \ ng[/tex]
