Complete question
The complete question is shown on the first uploaded image
Answer:
The value is [tex]K_c = 2.69 *10^{-5} [/tex]
Explanation:
From the question we are told that
The equation is
[tex]Fe_20_3_{(s)}+3H_{(g)}\to2Fe_{(s)}+3H_2O_{(g)}[/tex]
Generally the equilibrium is mathematically represented as
[tex]K_c = \frac{[H_2O]^2}{[H_2]^3}[/tex]
Here [tex][H_2O][/tex] is the concentration of water vapor which is mathematically represented as
[tex][H_2O ] = \frac{n_w}{V_s }[/tex]
Here [tex]V_s[/tex] is the volume of the solution given as 8.9 L
[tex]n_w[/tex] is the number of moles of water vapor which is mathematically represented as
[tex]n_w = \frac{m_w}{Z_w}[/tex]
Here [tex]m_w[/tex] is the mass of water given as 2.00 g
and [tex]Z_w[/tex] is the molar mass of water with value 18 g/mol
So
[tex]n_w = \frac{2}{18}[/tex]
=> [tex]n_w = 0.11 \ mol[/tex]
So
[tex][H_2O ] = \frac{0.11}{8.9 }[/tex]
=> [tex][H_2O ] = 0.01236 \ M [/tex]
Also
[tex][H][/tex] is the concentration of hydrogen gas which is mathematically represented as
[tex][H ] = \frac{n_v}{V_s }[/tex]
Here [tex]V_s[/tex] is the volume of the solution given as 8.9 L
[tex]n_v[/tex] is the number of moles of hydrogen gas which is mathematically represented as
[tex]n_v = \frac{m_v}{Z_v}[/tex]
Here [tex]m_w[/tex] is the mass of water given as 4.77 g
and [tex]Z_v[/tex] is the molar mass of water with value 2 g/mol
So
[tex]n_w = \frac{4.77}{2}[/tex]
=> [tex]n_w = 2.385 \ mol[/tex]
So
[tex][H_2O ] = \frac{2.385}{8.9 }[/tex]
=> [tex][H_2O ] = 0.265 \ M [/tex]
So
[tex]K_c = \frac{( 0.01236 )^3}{ (0.265 )^2}[/tex]
=> [tex]K_c = 2.69 *10^{-5} [/tex]
