Question

What is Kc at 800K? (The question is in the photo)

Answer 1

The value of Kc at 800K for the above reaction is 1.1642454865

Step-by-step explanation

Given that;

`\text{ CO}_((g))\text{ + H}_2O_((g))\rightleftarrows\text{ CO}_(2(g))\text{ + H}_(2(g))`

The number of moles of CO = 1 mol

The number of moles of H2O = 1 mol

The number of moles of CO2 = 0.519 mol

The volume of the vessel = 11L

To find the value of Kc, follow the steps below

Step 1: Write the equilibrium for the given reaction

`\begin{gathered} \text{ K}_c\text{ = }([products])/([reactants]) \\ \text{ } \\ \text{ K}_c\text{ = }([CO_2]*[H_2])/([CO]*[H_2O]) \end{gathered}`

Recall, that at equilibrium the mole of CO2 is 0.519 mol

Step 2: Find the mole of each reactant at equilibrium using the stoichiometry ratio

In the above reaction, 1 mole of CO reacts with 1 mole of H2O to give 1 mole of CO2 and 1 mole of H2

Let the number of moles of CO be x

`\begin{gathered} \text{ 1 mol CO }\rightarrow\text{ 1 mol CO}_2 \\ \text{ x mol CO }\rightarrow\text{ 0.519 CO}_2 \\ \text{ cross multiply} \\ \text{ x}*\text{ 1 = 0.519} \\ \text{ x = 0.519 mol} \end{gathered}`

The number of moles of CO is 0.519 mol

The next step is to find the number of moles of CO at equilibrium

At equilibrium, the number of mol of CO is calculated below

The number of moles of CO at equilibrium = 1 - 0.519

The number of moles of CO at equilibrium = 0.481 mol

Using stoichiometry ratio, the number of mole o water at equilibrium will also be 0.481 mol

Also, the number of moles of hydrogen at equilibrium is 0.519 mol

Step 3: Find Kc by substituting the calculated values into the formula

`\begin{gathered} \text{ K}_c\text{ at 800K = }(0.519*0.519)/(0.481*0.41) \\ \\ \text{ K}_C\text{ at 800K = }(0.269361)/(0.231361) \\ \text{ Kc at 800K = 1.1642454865} \end{gathered}`