Question

Chlorisondamine chloride (C₁₄H₂₀Cl₆N₂) is a drug used in the treatment of hypertension. A 1.28-g sample of a medication containing the drug was treated to destroy the organic material and to release all the chlorine as chloride ion. When the filtered solution containing chloride ion was treated with an excess of silver nitrate, 0.104 g silver chloride was recovered. Calculate the mass percent of chlorisondamine chloride in the medication, assuming the drug is the only source of chloride.

Short answer

The mass percent of C₁₄H₂₀Cl₆N₂is 4.05%.

Step-by-step solution

Conversion of mass

Convert the mass of AgCl into a mass of chlorine in chlorisondamine.

$$\begin{gathered} \mathbf{Mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{Cl}\mathbf{=}\mathbf{}\mathbf{mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{AgCl}\mathbf{}\mathbf{\times }\frac{\mathbf{1}\mathbf{mol}\mathbf{}\mathbf{AgCl}}{\mathbf{molar}\mathbf{}\mathbf{mass}\mathbf{}\mathbf{AgCl}}\mathbf{\times }\frac{\mathbf{1}\mathbf{mol}\mathbf{}{\mathbf{Cl}}^{\mathbf{-}}}{\mathbf{1}\mathbf{mol}\mathbf{}\mathbf{AgCl}}\mathbf{\times }\frac{\mathbf{molar}\mathbf{}\mathbf{mass}\mathbf{}{\mathbf{Cl}}^{\mathbf{-}}}{\mathbf{1}\mathbf{mol}\mathbf{}{\mathbf{Cl}}^{\mathbf{-}}} \\ \mathbf{Mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{Cl}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{104}\mathbf{g}\mathbf{\times }\frac{\mathbf{1}\mathbf{mol}\mathbf{}\mathbf{AgCl}}{\mathbf{143}\mathbf{.}\mathbf{4}\mathbf{g}}\mathbf{\times }\frac{\mathbf{1}\mathbf{mol}\mathbf{}{\mathbf{Cl}}^{\mathbf{-}}}{\mathbf{1}\mathbf{mol}\mathbf{}\mathbf{AgCl}}\mathbf{\times }\frac{\mathbf{35}\mathbf{.}\mathbf{45}\mathbf{g}}{\mathbf{1}\mathbf{mol}\mathbf{}{\mathbf{Cl}}^{\mathbf{-}}} \\ \mathbf{Mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{Cl}\mathbf{=}\mathbf{2}\mathbf{.}\mathbf{57}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{g} \end{gathered}$$

Determination of mass percent of chlorisondamine chloride

Molar mass of C₁₄H₂₀Cl₆N₂ = 429.02g/mol

From the formula, it can be seen that 6 moles of Cl for every mole of C₁₄H₂₀Cl₆N₂.

So, 212.70 g chlorine for every mole (492.02 g) of C₁₄H₂₀Cl₆N₂.

The mass of C₁₄H₂₀Cl₆N₂ is:

$$\begin{gathered} \mathbf{mass}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{C}}_{\mathbf{14}}{\mathbf{H}}_{\mathbf{20}}{\mathbf{Cl}}_{\mathbf{6}}{\mathbf{N}}_{\mathbf{2}}\mathbf{=}\mathbf{mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{chlorine}\mathbf{\times }\mathbf{mass}\mathbf{}\mathbf{ratio} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{=}\mathbf{2}\mathbf{.}\mathbf{57}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{g}\mathbf{\times }\frac{\mathbf{492}\mathbf{.}\mathbf{02}\mathbf{g}}{\mathbf{212}\mathbf{.}\mathbf{07}\mathbf{g}} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{=}\mathbf{5}\mathbf{.}\mathbf{18}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{g} \end{gathered}$$

The mass percent of C₁₄H₂₀Cl₆N₂ is:

$$\begin{gathered} \mathbf{mass}\mathbf{}\mathbf{\%}\mathbf{=}\frac{\mathbf{mass}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{C}}_{\mathbf{14}}{\mathbf{H}}_{\mathbf{20}}{\mathbf{Cl}}_{\mathbf{6}}{\mathbf{N}}_{\mathbf{2}}}{\mathbf{mass}\mathbf{}\mathbf{of}\mathbf{}\mathbf{sample}}\mathbf{\times }\mathbf{100} \\ \mathbf{mass}\mathbf{}\mathbf{\%}\mathbf{=}\frac{\mathbf{5}\mathbf{.}\mathbf{18}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{g}}{\mathbf{1}\mathbf{.}\mathbf{28}\mathbf{g}}\mathbf{\times }\mathbf{100} \\ \mathbf{mass}\mathbf{}\mathbf{\%}\mathbf{=}\mathbf{4}\mathbf{.}\mathbf{05}\mathbf{\%} \end{gathered}$$

Thus, the mass percent of C₁₄H₂₀Cl₆N₂ is 4.05%.