When 1.0 mol of ammonia gas in injected into a o.50L flask, the following reaction proceeds to equilibrium.
2NH3 <--> N2 (g) + 3H2 (g)
At equilibrium, 0.30 mol of hydrogen gas is present.
a) calculate the equilibrium concentrations of N2 and Nh3.
b) what is the value of Kc?
-- I understand the basic concept of calculating for k, I'm just confused about the coefficients and how to deal with them.
Looking at the coefficents, if .3 mol H2 was produced, then .2 mol of ammonia was used. Also, .1 mol of N2was generated.
k=[N][H2]^3 /[NH3]^2
I don't understand what your question about the coefficents is.
You can calculate the concentrations.
To calculate the equilibrium concentrations of N2 and NH3, we need to use the information provided and the balanced equation for the reaction. We are given that 0.30 mol of hydrogen gas (H2) is present at equilibrium.
The balanced equation for the reaction is: 2NH3 <--> N2 + 3H2
From the balanced equation, we can see that for every 2 moles of NH3 that react, 1 mole of N2 is produced. Similarly, for every 2 moles of NH3 that react, 3 moles of H2 are produced.
Given that 0.30 mol of H2 is produced, we can calculate the moles of NH3 that reacted:
3 moles H2 = 2 moles NH3
0.30 mol H2 = x mol NH3 (let x be the moles of NH3 that reacted)
Now we can find the total moles of NH3 at equilibrium:
Total moles of NH3 = Initial moles of NH3 - Moles of NH3 that reacted
Total moles of NH3 = 1.0 mol - x mol
Since we know that 0.30 mol of H2 is produced, this means that 0.20 mol of NH3 must have reacted:
Total moles of NH3 = 1.0 mol - 0.20 mol = 0.80 mol
Now that we have the total moles of NH3 at equilibrium, we can find the equilibrium concentrations using the given volume of the flask (0.50 L):
Concentration of NH3 (mol/L) = Total moles of NH3 / Volume of flask
Concentration of NH3 = 0.80 mol / 0.50 L = 1.6 M
Since the coefficients in the balanced equation are 2 for NH3 and 1 for N2, the equilibrium concentration of N2 will be half the equilibrium concentration of NH3:
Concentration of N2 = 1.6 M / 2 = 0.8 M
Now, to find the value of Kc (the equilibrium constant), we can use the concentrations of N2, H2, and NH3 at equilibrium:
Kc = [N2] * [H2]^3 / [NH3]^2
Kc = 0.8^1 * 0.3^3 / 1.6^2
Kc = 0.051
Therefore, the value of Kc for this reaction is 0.051.