Question

Question:How many moles of H⁺ions are present in the following aqueous solutions?

(a) 1.40 L of 0.25 M perchloric acid

(b) 6.8 mL of 0.92 M nitric acid

(c) 2.6 L of 0.085 M hydrochloric acid

Short answer

Answer

The moles of ions are present in the following aqueous solutions are:

(a) 0.35 mol${\mathit{H}}^{\mathbf{+}}$

(b)$\mathbf{6}\mathbf{.}\mathbf{26}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{3}\mathbf{}}\mathit{m}\mathit{o}\mathit{l}\mathbf{}{\mathit{H}}^{\mathbf{+}}$

(c) 0.221 mol${\mathit{H}}^{\mathbf{+}}$

Step-by-step solution

Calculate moles of  H+ ions released when  HCIO4 dissolve in water

The dissociation reaction of is:

$\mathit{H}\mathit{C}\mathit{I}{\mathit{O}}_{\mathbf{4}\mathbf{}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{\to }{\mathit{H}}^{\mathbf{+}\mathbf{}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathit{C}\mathit{I}{{\mathit{O}}^{\mathbf{-}}}_4\mathbf{\left(}\mathbf{aq}\mathbf{\right)}$

The moles of H⁺ is calculated as:

$$\begin{gathered} \mathit{m}\mathit{o}\mathit{l}\mathit{e}\mathit{s}\mathbf{}\mathit{o}\mathit{f}{\mathit{H}}^{\mathbf{+}}\mathbf{=}\mathbf{(}\mathbf{1}\mathbf{.}\mathbf{40}\mathbf{}\mathit{L}\mathbf{)}\mathbf{\left(}\frac{\mathbf{1}\mathbf{lit}}{\mathbf{1000}\mathbf{ml}}\mathbf{\left)}\mathbf{\right(}\frac{\mathbf{0}\mathbf{.}\mathbf{25}\mathbf{}{\mathbf{molHCIO}}_4}{\mathbf{Lit}}\mathbf{\left)}\mathbf{\right(}\frac{\mathbf{}\mathbf{1}\mathbf{}{\mathbf{molH}}^{\mathbf{+}}}{\mathbf{1}\mathbf{mol}\mathbf{}{\mathbf{HCIO}}_{\mathbf{4}}}\mathbf{\right)} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{35}\mathbf{}\mathit{m}\mathit{o}\mathit{l}{\mathit{H}}^{\mathbf{+}} \end{gathered}$$

Calculate moles of  ions released when  dissolve in water

The dissociation reaction of HN0₃ is:

$\mathit{H}\mathit{N}{\mathit{O}}_{\mathbf{3}\mathbf{}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{\to }{\mathit{H}}^{\mathbf{+}\mathbf{}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathbf{N}{\mathit{O}}_{\mathbf{3}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}$

The moles of H⁺ is calculated as:

role="math" localid="1663303487897" $$\begin{gathered} \mathit{m}\mathit{o}\mathit{l}\mathit{e}\mathit{s}\mathbf{}\mathit{o}\mathit{f}{\mathit{H}}^{\mathbf{+}}\mathbf{=}\mathbf{(}\mathbf{6}\mathbf{.}\mathbf{8}\mathbf{}\mathbf{mI}\mathbf{)}\mathbf{\left(}\frac{\mathbf{1}\mathbf{lit}}{\mathbf{1000}\mathbf{ml}}\mathbf{\left)}\mathbf{\right(}\frac{\mathbf{0}\mathbf{.}\mathbf{92}\mathbf{}{\mathbf{molHNO}}_{\mathbf{3}}}{\mathbf{Lit}}\mathbf{\left)}\mathbf{\right(}\frac{\mathbf{}\mathbf{1}\mathbf{}{\mathbf{molH}}^{\mathbf{+}}}{\mathbf{1}{\mathbf{molHNO}}_{\mathbf{3}}}\mathbf{\right)} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{=}\mathbf{6}\mathbf{.}\mathbf{26}\mathbf{}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{3}}\mathbf{}\mathit{m}\mathit{o}\mathit{l}{\mathit{H}}^{\mathbf{+}} \end{gathered}$$

Calculate moles of  ions released when HCl dissolve in water

The dissociation reaction of HCl is:

$\mathit{H}\mathit{C}\mathit{I}\mathbf{}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{\to }{\mathit{H}}^{\mathbf{+}\mathbf{}}\mathit{C}{\mathit{I}}^{\mathbf{-}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}$

The moles role="math" localid="1663303293665" ${\mathit{H}}^{\mathbf{+}}$of is calculated as:

$$\begin{gathered} \mathit{m}\mathit{o}\mathit{l}\mathit{e}\mathit{s}\mathbf{}\mathit{o}\mathit{f}{\mathit{H}}^{\mathbf{+}}\mathbf{=}\mathbf{(}\mathbf{2}\mathbf{.}\mathbf{6}\mathbf{}\mathit{L}\mathbf{)}\mathbf{\left(}\frac{\mathbf{0}\mathbf{.}\mathbf{85}\mathbf{}\mathbf{m}\mathbf{o}\mathbf{l}\mathbf{}\mathbf{H}\mathbf{C}\mathbf{I}}{\mathbf{LIt}}\mathbf{\left)}\mathbf{\right(}\frac{\mathbf{}\mathbf{1}\mathbf{}{\mathbf{molH}}^{\mathbf{+}}}{\mathbf{1}\mathbf{molHCI}}\mathbf{\right)} \\ \mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{221}\mathit{m}\mathit{o}\mathit{l}{\mathit{H}}^{\mathbf{+}} \end{gathered}$$