Q18P - Chemistry: Molecular Nature Of Matter And Change

Question

Balance each of the following examples of heterogeneous

equilibria and write its reaction quotient, Qc:

$$\begin{gathered} \mathbf{\left(}\mathbf{a}\mathbf{\right)}\mathbf{ }{\mathbf{Na}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{2}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{+}{\mathbf{CO}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ }\mathbf{ }\mathbf{𝆏}\mathbf{ }\mathbf{ }\mathbf{ }{\mathbf{Na}}_{\mathbf{2}}{\mathbf{CO}}_{\mathbf{3}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{+}{\mathbf{O}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)} \\ \mathbf{\left(}\mathbf{b}\mathbf{\right)}\mathbf{ }{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\left(}\mathbf{I}\mathbf{\right)}\mathbf{ }\mathbf{ }\mathbf{𝆏}\mathbf{ }\mathbf{ }\mathbf{ }{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\left(}\mathbf{g}\mathbf{\right)} \\ \mathbf{\left(}\mathbf{c}\mathbf{\right)}\mathbf{ }{\mathbf{NH}}_{\mathbf{4}}\mathbf{CI}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{ }\mathbf{𝆏}\mathbf{ }\mathbf{ }\mathbf{ }{\mathbf{NH}}_{\mathbf{3}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{+}\mathbf{HCI}\mathbf{\left(}\mathbf{g}\mathbf{\right)} \end{gathered}$$

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.

$$\begin{gathered} \left(\mathrm{a}\right) 2{\mathrm{Na}}_2{\mathrm{O}}_2\left(\mathrm{s}\right)+2{\mathrm{CO}}_2\left(\mathrm{g}\right) 𝆏 2{\mathrm{Na}}_2{\mathrm{CO}}_3\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right) \\ {\mathrm{Q}}_{\mathrm{o}}=\frac{{\left[{\mathrm{Na}}_2{\mathrm{O}}_3\right]}^2\left[{\mathrm{O}}_2\right]}{{\left[{\mathrm{Na}}_2{\mathrm{O}}_2\right]}^2{\left[{\mathrm{CO}}_2\right]}^2} \\ \left(\mathrm{b}\right) {\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right) 𝆏 {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right) \\ {\mathrm{Q}}_{\mathrm{o}}=\frac{\left[ {\mathrm{H}}_2\mathrm{O}\right]}{\left[ {\mathrm{H}}_2\mathrm{O}\right]} \\ \left(\mathrm{c}\right) 3{\mathrm{NH}}_4\mathrm{CI}\left(\mathrm{s}\right) 𝆏 3{\mathrm{NH}}_3\left(\mathrm{g}\right)+3\mathrm{HCI}\left(\mathrm{g}\right) \\ {\mathrm{Q}}_{\mathrm{o}}=\frac{{\left[ {\mathrm{NH}}_3\right]}^3{\left[\mathrm{HCI}\right]}^3}{{\left[ {\mathrm{NH}}_4\mathrm{CI}\right]}^3} \end{gathered}$$

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

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

Reaction quotient ,

${\mathrm{Q}}_{\mathrm{o}}=\frac{{\left[N{a}_2{\mathrm{O}}_3\right]}^2\left[{\mathrm{O}}_2\right]}{{\left[N{a}_2{\mathrm{O}}_2\right]}^2{\left[C{O}_2\right]}^2}$

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

${\mathrm{H}}_2\mathrm{O}\left(\mathrm{I}\right) 𝆏 {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

Reaction quotient ,

$$\begin{gathered} {\mathrm{Q}}_{\mathrm{o}}=\frac{\left[ {\mathrm{H}}_2\mathrm{O}\right]}{\left[ {\mathrm{H}}_2\mathrm{O}\right]} \\ =1 \end{gathered}$$

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

$3{\mathrm{NH}}_4\mathrm{CI}\left(\mathrm{s}\right) 𝆏 3{\mathrm{NH}}_3\left(\mathrm{g}\right)+3\mathrm{HCI}\left(\mathrm{g}\right)$

Reaction quotient ,

${\mathrm{Q}}_{\mathrm{o}}=\frac{{\left[ N{H}_3\right]}^3{\left[HCI\right]}^3}{{\left[ N{H}_{4}CI\right]}^3}$