Answer:
![K_{c} = [\text{C}]^{2}[\text{[D]}](https://tex.z-dn.net/?f=K_%7Bc%7D%20%3D%20%5B%5Ctext%7BC%7D%5D%5E%7B2%7D%5B%5Ctext%7B%5BD%5D%7D)
Explanation:

The general formula for an equilibrium constant expression is
![K_{c} = \dfrac{[\text{Products}]}{[\text{Reactants}]}](https://tex.z-dn.net/?f=K_%7Bc%7D%20%3D%20%5Cdfrac%7B%5B%5Ctext%7BProducts%7D%5D%7D%7B%5B%5Ctext%7BReactants%7D%5D%7D)
Solids and liquids are not included in the equilibrium constant expression.
Thus, for this reaction,
![K_{c} = [\textbf{C}]^{\mathbf{2}}\textbf{[D]}](https://tex.z-dn.net/?f=K_%7Bc%7D%20%3D%20%5B%5Ctextbf%7BC%7D%5D%5E%7B%5Cmathbf%7B2%7D%7D%5Ctextbf%7B%5BD%5D%7D)
The single combination of pressure and temperature at which liquid water, solid ice, and water vapor can coexist in a stable equilibrium occurs at approximately 273.1575 K (0.0075 °C; 32.0135 °F) and a partial vapor pressure of 611.657 pascals (6.11657 mbar; 0.00603659 atm).[4][5] At that point, it is possible to change all of the substance to ice, water, or vapor by making arbitrarily small changes in pressure and temperature. And the temperature is called Triple point