Given the following reaction at equilibrium, if Kc = 1.90 x 1019 at 25.0 °C, Kp = __________.
H2 (g) + Br2 (g) ↔ 2 HBr (g)
1.90X10^19 it would remain the same
Kp = Kc(RT)^delta n
To find the expression for Kp, we can use the equation:
Kp = Kc(RT)^(Δn)
where:
Kp = equilibrium constant in terms of partial pressures
Kc = equilibrium constant in terms of molar concentrations
R = ideal gas constant (0.0821 L.atm/mol.K)
T = temperature in Kelvin (25°C = 298.15 K)
Δn = change in moles of gas products - change in moles of gas reactants
In the given equation:
H2 (g) + Br2 (g) ↔ 2 HBr (g)
We can see that there is a decrease in the number of moles of gas species from the reactant side to the product side.
Δn = 2 - 1 - 1 = 0
Substituting the given values:
Kp = Kc(RT)^(Δn)
Kp = (1.90 x 10^19)(0.0821 L.atm/mol.K)(298.15 K)^0
Since any number raised to the power of zero is equal to 1, we have:
Kp = 1.90 x 10^19
Therefore, Kp = 1.90 x 10^19.
To find Kp, we need to understand the relationship between Kc and Kp for a given chemical reaction. Kc represents the equilibrium constant based on the concentration of the reactants and products, while Kp represents the equilibrium constant based on the partial pressures of the reactants and products.
For the given reaction: H2 (g) + Br2 (g) ↔ 2 HBr (g), we can determine the relationship between Kc and Kp by considering the stoichiometry of the reaction. The stoichiometric coefficients in the balanced equation indicate the molar ratios between the reactants and products.
In this case, the balanced equation shows that for every 1 mole of H2 and Br2, 2 moles of HBr are produced. Therefore, the equilibrium expression can be written as:
Kc = [HBr]^2 / [H2] * [Br2]
The square brackets represent the concentration of each species at equilibrium. To relate Kc to Kp, we need to use the ideal gas law, which states that the pressure of an ideal gas is directly proportional to its concentration.
For a gas reaction, we can express the equilibrium constant Kp in terms of the partial pressures:
Kp = (P(HBr))^2 / (P(H2) * P(Br2))
where P(HBr), P(H2), and P(Br2) denote the partial pressures of HBr, H2, and Br2, respectively.
Therefore, to solve for Kp, you would need to know the values of the partial pressures of HBr, H2, and Br2 at equilibrium. Given only the value of Kc, it is not possible to directly determine Kp without additional information.
If you were provided with the concentrations of HBr, H2, and Br2, you could use the ideal gas law to convert those concentrations to partial pressures and then calculate Kp using the equation mentioned earlier.