For the reaction H2(g) + CO2(g) ⇌ H2O(g) + CO(g) at 700ºC, Kc = 0.534. Calculate the number of moles of H2 that are present at equilibrium if a mixture of 0.300 mole of CO and 0.300 mole of H2O is heated to 700ºC in a 10.0-L container.

Respuesta :

Answer:

[tex][H_2]_{eq}=0.0173M[/tex]

Explanation:

Hello,

In this case, for the given reaction, the law of mass action turns out:

[tex]Kc=\frac{[H_2O][CO]}{[H_2][CO_2]}[/tex]

In such a way, the reactants initial concentrations are:

[tex][CO_2]_0=[H_2]_0=\frac{0.300mol}{10.0L} =0.030M[/tex]

And considering the change [tex]x[/tex] due to the equilibrium, the law of mass action takes the following form:

[tex]Kc=\frac{(x)(x)}{(0.030M-x)(0.030M-x)} =\frac{x^2}{0.0009-0.06x+x^2} \\Kc(0.0009-0.06x+x^2)=x^2\\0.0004806-0.03204x+0.534x^2-x^2=0\\0.466x^2+0.03204x-0.0004806=0\\x_1=-0.0814M\\x_2=0.0127M[/tex]

The feasible answer is [tex]x=0.0127M[/tex]

Therefore, the hydrogen moles at equilibrium are:

[tex][H_2]_{eq}=0.030M-0.0127M=0.0173M[/tex]

Best regards.

The number of moles of H2 present at equilibrium is 0.04moles

Data;

  • Kc = 0.534
  • CO = 0.3mol
  • H2O = 0.30mol
  • V = 10L
  • T = 700ºC

Equilibrium Concentration

let's find the concentration of the species in the reaction.

The concentration of CO is

[tex][CO] = \frac{0.3}{10} = 0.03M[/tex]

The concentration of H2O is

[tex][H_2O] = \frac{0.3}{10} 0.03M[/tex]

The equation of this reaction is

                H2(g) + CO2(g) ⇌ H2O(g) + CO(g)

final           -x           -x            0.03 + x     0.03 + x

The Kc i.e the equilibrium constant of this reaction is

[tex]K_c = \frac{[product]}{[reactant]}\\[/tex]

let's substitute the values and solve.

[tex]K_c = \frac{product}{reactant} \\0.534 = \frac{(0.03+x)(0.03+x)}{x * x} \\x= 0.04M[/tex]

The number of moles of H2 present at equilibrium can be calculated as

[tex]0.04 = \frac{0.04}{1}[/tex]

The number of moles of H2 present at equilibrium is 0.04moles

Learn more on equilibrium concentration constant here;

https://brainly.com/question/26658889