Question

Consider the reaction CO(g) + NH₃(g) ⇌ HCONH₂(g), K = 2.70 at 550 K. If a reaction vessel initially contains only CO and NH₃ at partial pressures of 3.00 bar and 3.00 bar, respectively, what will be the partial pressure of HCONH₂ at equiLiBrium?

Answer 1

To find the equilibrium partial pressure of HCONH₂, one must use an ICE table and the equilibrium constant to solve for x, which represents the change in pressure of the reactants and products. The final equilibrium partial pressure of HCONH₂ is equal to the value of x obtained after solving the quadratic equation.

Step-by-step explanation:

The objective is to determine the partial pressure of HCONH₂ at equilibrium when CO and NH₃ gases react according to the equation CO(g) + NH₃(g) ⇌ HCONH₂(g). Also, their initial pressures and the equilibrium constant are denoted by K at a specific temperature. We can use an ICE table and the given equilibrium constant to solve this.

Step 1: Set up an ICE table:

Initial pressures: P(CO) = 3.00 bar, P(NH₃) = 3.00 bar, P(HCONH₂) = 0 bar

Change in pressures: P(CO) = -x, P(NH₃) = -x, P(HCONH₂) = +x

Equilibrium pressures: P(CO) = 3.00 - x, P(NH₃) = 3.00 - x, P(HCONH₂) = 0 + x

Step 2: Write the equilibrium expression: K = P(HCONH₂) / (P(CO) × P(NH₃))

Step 3: Substitute the equilibrium pressures into the K expression and solve for x: 2.70 = x / ((3.00 - x)(3.00 - x))

Step 4: Solve the quadratic equation for x to find the change in pressure.

Step 5: Calculate the equilibrium partial pressure of HCONH₂ using the value of x.

Through these steps we can determine the partial pressure of HCONH₂ at equilibrium to be the value of x calculated in step 4, assuming that x is significantly smaller than the initial pressures of CO and NH₃, so that 3.00 - x is approximately equal to 3.00.