Calculating Equilibrium Concentrations?

CO(g)+NH3(g)⇌HCONH2(g), Kc=0.830
If a reaction vessel initially contains only CO and NH3 at concentrations of 1.00 M and 2.00 M, respectively, what will the concentration of HCONH2 be at equilibrium?
Posted: August 14, 2013

Best Answer

ICE, ICE, baby ...
CO(g) + NH3(g) ⇌ HCONH2(g),
Kc = (products)/(reactants)
Kc = [HCONH2]/([CO][NH3])
Set up an ICE table
Species.....Initial...Change...Equil...
CO............1.00 M....-x........1.00-x.
NH3...........2.00 M....-x.......2.00-x.
HCONH2.......0.........+x.........x..
Kc = [HCONH2]/([CO][NH3])
Kc = 0.830 = (x)/((1.00 - x)*(2.00 - x))
Multiply this out to get a quadratic equation:
(0.830)*((1.00 - x)*(2.00 - x)) = x
(0.830)*(2 - 3x + x^2) = x
1.66 - 2.49x + x^2 = x
x^2 - 3.49x + 1.66 = 0
Use the quadratic formula to solve for the roots of this equation.
negative root = 0.5681
positive root = 2.9219
We reject the positive root (it is greater than the starting amount of NH3, so it is unrealistic), so
x = 0.5681
We plug that back into the ICE table to determine the equilibrium quantities.
Species.......Equil...
CO..............1.00-x = (1.00 - 0.5681) = 0.4319 M
NH3............2.00-x = (2.00 - 0.5681) = 1.4319 M
HCONH2......x = 0.5681 M
So at equilibrium, [HCONH2] = 0.5681 M

Related Questions

1+
answers
Equilibrium Chemistry Help
Initially there were equilibrium concentrations of 0.1514 M A, 0.1917 M B. Which of the equations below is correct if the pressure increased by a factor of 2.24...
May 10, 2013
1+
answers
Find Equilibrium Concentration When You're Given Kc And The Reactant Concentration
I was just wondering.. the equilibrium concentration of a product when you are given the value for the equilibrium constant (Kc) and the equilibrium concentrati...
May 10, 2013
2+
answers
Calculating Ka From Given Concentrations, Volume And Ph?
To calculate the Ka I know I can find the [H30+] from the pH and plug that into the Ka expression with the given concentrations, but I was wondering if I need t...
May 10, 2013
1+
answers
The Following Reaction 2so3(g)<->2so2(g)+02(g)?
Has a equilibrium constant equal to 0.23M. If the following concentrations are present: [SO2]=0.480M, [O2]=0.561M, [SO3]=0.220M, is the reaction equilibrium? If...
May 10, 2013
1+
answers
Help In Equilibrium Constant
the following reaction has an equilibrium constant of (6.2)(10^2) at a certain temperature. calculate the equilibrium concentrations of all species if 4.5 mol o...
May 10, 2013
1+
answers
Chem Question Please Answer This. 10 Pts.?
At a certain temperature, Keq = 10.5 for the equilibrium below. CO(g) + 2 H2(g) equilibrium reaction arrow CH3OH(g) Calculate the following concentrations. (...
May 10, 2013
1+
answers
If The Initial Volume Of The Reaction Vessel Was Halved, While The Temperature Remains Constant
what would the new equilibrium concentrations be? The original concentrations were: [A]=0.20 [B]=0.30 M, and [C]=0 30 [C]=0.30 M ...
May 10, 2013
2+
answers
Chemistry Test Help!?
Here's a question: In certain conditions, the equilibrium concentrations for components in the reaction 2NOCl(g) 2NO(g) + Cl2(g) are [NO] = 0.02 M, [Cl2] = 0....
May 20, 2013
1+
answers
I Need To Help For This Question!(solution Must Be Detailed)?
For the all-gas system: 2X+Y 3Z K=0.34 Starting with 0.90 M concentrations of X and Y, it was found that the equilibrium concentration of X was 0.60 M. What ...
June 14, 2013
2+
answers
Chemistry Assistance Please?
Can you me with these three problems? I got them wrong on my test... Please explain, and thanks in advance! -------------------- 4 - A solution of CuCO3 ha...
May 29, 2013
1+
answers
Equilibrium Problem Ap Chem
At a certain temperature equilibrium for the following reaction was established PCl5(g) PCl3(g) + Cl2(g) Analysis of the mixture showed that the equilib...
May 10, 2013
1+
answers
Lechateliers Quiz^^ Best Answer Is Most Higher People?
matching A. LeChateliers principle B. equilibrium constant C. chemical equilibrium D.stress E.equilibrium expression 1_ A system in which two opposing rea...
May 20, 2013
2+
answers
For The Reaction Shown? 2h2o(g) <<--->> 2h2(g) + O2(g)?
the equilibrium concentrations were found to be [H2O]= 0.250 M [H2]= 0.470 M [O2]= 0.800 M equilibrium constant for this reaction ...
August 14, 2013
1+
answers
What Are Examples Of Dynamic Equilibrium?
So I have to answer this question, please any help helps Throughout the trimester we have had many examples of dynamic equilibrium. Describe what dynamic equi...
June 14, 2013
1+
answers
The Haber Process For The Manufacture Of Ammonia Is Shown Below: N2(g) + 3h2(g) 2nh3(g)?
An equilibrium mixture in a sealed 2 dm3 container at 700K and a pressure of 200kPa contains 0.6 mol of nitrogen, 2.0 mol of hydrogen and 0.6 mol of ammonia. Ca...
June 14, 2013

Page Loaded:0.02