For the reaction below, KP = 1.6 × 106 at 400.0 °C. HCHO2( g ) <--> CO( g ) + H2O( g ) A mixture of CO( g ) and H2O(l ) was prepared in a 2.00 L reaction vessel at 25 °C in which the pressure of CO was 0.177 atm. The mixture also contained 0.391 g of H2O. The vessel was sealed and heated to 400 °C. When equilibrium was reached, what was the partial pressure of the HCHO2 at 400 °C ?

mol H2O = 0.391/18 = about 0.02 mols but you need to do it more accurately. Then use PV = nRT to calculate P at 400 C. I get about 0.6 atm.

P CO = 0.177 atm at 25. Convert to P at 600. I obtained approximately 0.4 atm.
........HCHO2 ==> CO + H2O
I........0........0.4...0.6
C........x........-x.....-x
E........x......0.4-x..0.6-x
Kp = 1.6E6 = pCO*pH2O/pHCHO2
Substitute the E line and from the ICE chart and solve for x = pHCHO2 in atm. Post your work if you get stuck.

0.200

To solve this problem, we need to use the given value of KP and the initial conditions to calculate the partial pressure of HCHO2 at 400 °C.

1. Convert the given mass of H2O to moles:
We can use the molar mass of H2O to convert the mass to moles.
Molar mass of H2O = 18.015 g/mol
Number of moles of H2O = (0.391 g) / (18.015 g/mol)

2. Calculate the initial partial pressure of CO:
Given pressure of CO = 0.177 atm

3. Use the ideal gas law to calculate the number of moles of CO:
PV = nRT
n = (PV) / RT
where:
P = pressure (0.177 atm)
V = volume (2.00 L)
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature (25 + 273 = 298 K)

4. Calculate the initial number of moles of HCHO2:
According to the balanced equation, HCHO2 is a reactant, so its initial number of moles is zero.

5. Use the given KP and the calculated initial moles to determine the equilibrium moles of HCHO2:
KP = (nCO · nH2O) / nHCHO2
Rearrange the equation to solve for nHCHO2:
nHCHO2 = (nCO · nH2O) / KP
Substitute the calculated values:
nHCHO2 = (0 · (0.391 g / 18.015 g/mol)) / (1.6 × 10^6)

6. Convert the equilibrium moles of HCHO2 to partial pressure:
Using the ideal gas law, PV = nRT, we can solve for P:
P = (nHCHO2 · R · T) / V
where:
nHCHO2 = equilibrium moles of HCHO2 (calculated in step 5)
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature (400 + 273 = 673 K)
V = volume (2.00 L)

Solving the equation will give you the partial pressure of HCHO2 at 400 °C.

To find the partial pressure of HCHO2 at 400 °C, we need to use the initial and equilibrium conditions along with the given value of KP.

Step 1: Convert the mass of H2O to moles:
Given: Mass of H2O = 0.391 g
Molar mass of H2O = 18.015 g/mol
Number of moles of H2O = (0.391 g) / (18.015 g/mol)

Step 2: Calculate the initial moles of CO:
As per the reaction equation, the mole ratio between CO and H2O is 1:1. Therefore, the number of moles of CO will be equal to the number of moles of H2O calculated in step 1.

Step 3: Calculate the initial pressure of CO:
Given: Pressure of CO = 0.177 atm
Vessel volume = 2.00 L
According to the ideal gas law, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
Rearranging the equation, we have P = (nRT) / V.
Substituting the calculated value of n and the given values of V (2.00 L) and T (25 °C converted to Kelvin), calculate the initial pressure of CO.

Step 4: Calculate the equilibrium moles of HCHO2:
Using KP, the equilibrium constant, we can set up an expression to relate the moles of HCHO2, CO, and H2O at equilibrium.
Since KP = (PHCHO2 / P(CO) * PH2O), where PHCHO2, P(CO), and PH2O are the partial pressures of HCHO2, CO, and H2O at equilibrium, respectively.
Rearrange the equation to solve for the moles of HCHO2 at equilibrium:
(nHCHO2)eq = KP * (nCO)eq * (nH2O)eq
Using the values we obtained earlier for moles of CO and H2O.

Step 5: Calculate the partial pressure of HCHO2 at equilibrium:
Using the ideal gas law, we can now calculate the partial pressure of HCHO2 at equilibrium.
PV = nRT
Rearranging the equation, P = (nRT) / V.
Substituting the calculated value of (nHCHO2)eq and the given values of V (2.00 L) and T (400 °C converted to Kelvin), calculate the partial pressure of HCHO2 at 400 °C.

Following these steps will allow you to determine the partial pressure of HCHO2 at 400 °C based on the provided information.