Q19P - Chemistry: Molecular Nature Of Matter And Change

Question

Balance each of the following examples of heterogeneous()

equilibria and write its reaction quotient, Qc:

$$\begin{gathered} \mathbf{\left(}\mathbf{a}\mathbf{\right)}\mathbf{ }{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\left(}\mathbf{I}\mathbf{\right)}\mathbf{+}{\mathbf{SO}}_{\mathbf{3}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ }\mathbf{ }\mathbf{𝆏}\mathbf{ }{\mathbf{H}}_{\mathbf{2}}{\mathbf{SO}}_{\mathbf{4}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)} \\ \mathbf{\left(}\mathbf{b}\mathbf{\right)}\mathbf{ }{\mathbf{KNO}}_{\mathbf{3}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{ }\mathbf{ }\mathbf{𝆏}\mathbf{ }{\mathbf{KNO}}_{\mathbf{2}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{ }\mathbf{+}\mathbf{ }{\mathbf{O}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)} \\ \mathbf{\left(}\mathbf{c}\mathbf{\right)}\mathbf{ }{\mathbf{S}}_{\mathbf{8}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{ }\mathbf{+}\mathbf{ }{\mathbf{F}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ }\mathbf{𝆏}\mathbf{ }\mathbf{ }{\mathbf{SF}}_{\mathbf{6}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ } \end{gathered}$$

Step-by-Step Solution

Answer

A reaction quotient $\left(Q_c\right)$ can create from a balanced chemical equation. Products and reactants are written in numerator and denominator with their coefficients as power and they are multiplied.

$$\begin{gathered} \left(\mathrm{a}\right) {\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)+{\mathrm{SO}}_3\left(\mathrm{g}\right) 𝆏 {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right) \\ Q_o=\frac{\left[ {\mathrm{H}}_2{\mathrm{SO}}_4\right]}{\left[ {\mathrm{H}}_2\mathrm{O}\right]\left[{\mathrm{SO}}_3\right]} \\ \left(\mathrm{b}\right) 2{\mathrm{KNO}}_3\left(\mathrm{s}\right) 𝆏 2{\mathrm{KNO}}_2\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \\ Q_o=\frac{{\left[ {\mathrm{KNO}}_2\right]}^2\left[ {\mathrm{O}}_2\right]}{{\left[{\mathrm{KNO}}_3\right]}^2} \\ \left(\mathrm{c}\right) {\mathrm{S}}_8\left(\mathrm{s}\right) + 24{\mathrm{F}}_2\left(\mathrm{g}\right) 𝆏 8{\mathrm{SF}}_6\left(\mathrm{g}\right) \\ Q_o=\frac{{\left[ {\mathrm{SF}}_6\right]}^8}{\left[ {\mathrm{S}}_8\right]{\left[{\mathrm{F}}_2 \right]}^{24}} \end{gathered}$$

Step 1: Reaction quotient of ( Q c )   o f   ( a )

${\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right)+{\mathrm{SO}}_3\left(\mathrm{g}\right) 𝆏 {\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)$

  Reaction quotient $\left(Q_C\right)$

$Q_o=\frac{\left[ {\mathrm{H}}_{2}S{O}_4\right]}{\left[ {\mathrm{H}}_2\mathrm{O}\right]\left[S{O}_3\right]}$

Step 2: Reaction quotient of ( Q c )   o f   ( b )

$2{\mathrm{KNO}}_3\left(\mathrm{s}\right) 𝆏 2{\mathrm{KNO}}_2\left(\mathrm{s}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)$

   Reaction quotient $\left(Q_c\right)$

$Q_o=\frac{{\left[ KN{O}_2\right]}^2\left[ {\mathrm{O}}_2\right]}{{\left[KN{O}_3\right]}^2}$

Step 3: Reaction quotient of ( Q c )   o f   ( c )

${\mathrm{S}}_8\left(\mathrm{s}\right) + 24{\mathrm{F}}_2\left(\mathrm{g}\right) 𝆏 8{\mathrm{SF}}_6\left(\mathrm{g}\right)$

  Reaction quotient $\left(Q_c\right)$

$Q_o=\frac{{\left[ S{F}_6\right]}^8}{\left[ {\mathrm{S}}_8\right]{\left[{\mathrm{F}}_2 \right]}^{24}}$