H2S decomposes at 438k ,according to the following equilibrium:
H2S(g)=H2(g)+S(s)
Knowing that Kc=1.1*10-2,determine the gram amount of sulfur formed at the equilibrium coditions in a 5L flask ,where the initial concentration of H2S was 0.7M.
Also,calculate Kp.
......H2S ==> H2 + S(s)
I.....0.7.....0.....0
C.....-x......x.....-
E...0.7-x.....x.....-
NOTE that S is a solid and isn't in the Kc expression: Kc = (H2)/(H2S)
Substitute the E line into Kc expression and solve for x = (H2) in mols/L.
The problem asks for grams S and that isn't anywhere in Kc. But you know that 1 mols S is formed for every 1 mol H2 produced. Therefore, convert M H2 to mols in a 5L container.
mols H2 = M H2 x 5L = ? and convert mols H2 = mols S.
Then grams S = mols S x molar mass S = ?
Find Kp by Kp = Kc(RT)^delta n.
Remember S is a solid and not a gas.
To determine the gram amount of sulfur formed at the equilibrium conditions, we need to use the equilibrium constant (Kc) and the initial concentration of H2S.
Given:
Initial concentration of H2S = 0.7 M
Equilibrium constant (Kc) = 1.1 * 10^-2
Step 1: Write the balanced chemical equation.
H2S(g) ⇌ H2(g) + S(s)
Step 2: Set up an ICE table to determine the concentration of each species at equilibrium.
Initial: H2S(g) ⇌ H2(g) + S(s)
0.7 M 0 M 0 M
Change: -x M +x M +x M
Equilibrium: 0.7 - x M x M x M
Step 3: Plug the equilibrium concentrations into the equilibrium constant expression.
Kc = ([H2(g)] * [S(s)]) / [H2S(g)]
Given:
[H2S(g)] = 0.7 - x
[H2(g)] = x
[S(s)] = x
Using the given Kc value:
1.1 * 10^-2 = (x * x) / (0.7 - x)
Step 4: Solve the equation for x (amount of sulfur formed). As the equilibrium constant expression is quadratic, we can solve it using the quadratic formula.
1.1 * 10^-2 = (x^2) / (0.7 - x)
1.1 * 10^-2 * (0.7 - x) = x^2
1.54 * 10^-2 - (1.1 * 10^-2 * x) = x^2
x^2 + (1.1 * 10^-2 * x) - 1.54 * 10^-2 = 0
Solving this quadratic equation will give us the value of x, which represents the amount of sulfur formed at equilibrium.
Now, let's calculate Kp.
Kp is related to Kc through the equation:
Kp = Kc * (RT)^Δn
Where:
R = Gas constant (0.0821 L * atm / K * mol)
T = temperature in Kelvin (convert 438°C to Kelvin)
Δn = Change in moles of gas (1 - 1 = 0, as H2O = H2(g) - S(s)).
Calculate T (temperature in Kelvin):
Temperature in Kelvin = 438°C + 273.15
Calculate Kp:
Kp = Kc * (RT)^0
Substituting the values into the equation will give us the value of Kp.
Please let me know if you'd like me to assist you further with the calculations.