Question

If a mixture of reactants and products contains 0.035 M H20, 0.050 M CH4, 0.15 MCO, and 0.20 M H2. For the reaction: H2O (g) + CH4 (g) = CO (g) + 3 H2(g) Kc = 4.7 at 1400 K. In which direction does the reaction proceed to reach equilibrium? What is the value of Kp? 9. Write the equilibrium constant expression Kc for: C2H4OH (aq) + 0, (aq)=CH-COH (aq) + H2O (0)

Answer 1

Answer : The reaction must shift to the product (right) to be in equilibrium.

The value of
`K_p` is
`6.2* 10^(4)`

Explanation :

Reaction quotient (Q) : It is defined as the measurement of the relative amounts of products and reactants present during a reaction at a particular time.

The given balanced chemical reaction is,

`H_2O(g)+CH_4(g)\rightarrow CO(g)+3H_2(g)`

The expression for reaction quotient will be :

`Q=([CO][H_2]^3)/([H_2O][CH_4])`

In this expression, only gaseous or aqueous states are includes and pure liquid or solid states are omitted.

Now put all the given values in this expression, we get

`Q=((0.15)* (0.20)^3)/((0.035)* (0.050))=0.686`

The given equilibrium constant value is,
`K_c=4.7`

Equilibrium constant : It is defined as the equilibrium constant. It is defined as the ratio of concentration of products to the concentration of reactants.

There are 3 conditions:

When
`Q>K_c` that means product > reactant. So, the reaction is reactant favored.

When
`Q<K_c` that means reactant > product. So, the reaction is product favored.

When
`Q=K_c` that means product = reactant. So, the reaction is in equilibrium.

From the above we conclude that, the
`Q<K_c` that means product < reactant. So, the reaction is product favored that means reaction must shift to the product (right) to be in equilibrium.

Now we have to calculate the value of
`K_p`

The relation between
`K_p` and
`K_c` are :

`K_p=K_c* (RT)^(\Delta n)`

where,

`K_p` = equilibrium constant at constant pressure = ?

`K_c` = equilibrium concentration constant = 4.7

R = gas constant = 0.0821 L⋅atm/(K⋅mol)

T = temperature = 1400 K

`\Delta n` = change in the number of moles of gas = [(3 + 1) - (1 + 1)] = 2

Now put all the given values in the above relation, we get:

`K_p=4.7* (0.0821L.atm/K.mol* 1400K)^(2)`

`K_p=6.2* 10^(4)`

Thus, the value of
`K_p` is
`6.2* 10^(4)`