Final answer:
The Keq for the reaction at 25°C is 157.2 and finding partial pressures of B(g) and D(g) at a total system pressure of 4.3 atm involves using the equilibrium constant expression for gaseous reactions, excluding solids from the Kp expression and solving algebraically.
Step-by-step explanation:
The equilibrium constant (Keq) for the reaction A(s) + B(g) = C(s) + D(g) at 25°C is given as 157.2. To find the partial pressures of B(g) and D(g) when the total pressure of the system is 4.3 atm, we need to apply the concept of equilibrium and use the ideal gas law and the expression for Keq for gaseous reactions. Typically, for gaseous systems in equilibrium, the equilibrium constant is expressed in terms of partial pressures and designated Kp.
In this equation, the solid substances A and C do not contribute to the pressure and thus are not included in the Kp expression. The equilibrium constant equation can be written as:
Kp = (PD/PB)
where PB and PD are the partial pressures of B and D, respectively. Since we know the total pressure and the equilibrium constant, we can set up an equation to solve for the partial pressures of B and D. This involves setting the ratio of the partial pressures of D to B equal to the Keq, and then accounting for the total pressure in the system to find the individual pressures of B and D.
The equilibrium calculations can be complex and often involve algebraic methods to solve for the unknown partial pressures. Since we do not have the concentration or pressure for A and B initially, we cannot directly calculate the partial pressures of B and D without additional information or assumptions about the system's behavior at equilibrium.