# Question #f80a2

##### 1 Answer

**Given reversible gaseous rection**

#color(red)(AB(g)rightleftharpoonsA(g)+B(g))#

**ICD Table**

Where

#color(blue)(" "AB(g)" "rightleftharpoons" "A(g)" "+" "B(g))#

Where

Now let

**In the desired state of 50% dissociation**

*the total number of moles* in the reaction mixture is

Mole fraction of

Mole fraction of

Mole fraction of

We know

#color(red)(p_i=chi_ixxP)#

Where

So

Partial pressure of

Partial pressure of

Partial pressure of

Now the **Reaction Quotient in respect of pressure** at the desired state of 50% dissociation.

#Q_p=(p_"A(g)"xxp_B(g))/p_"AB(g)"#

Inserting the values of partial pressure we get

#Q_p=((alphaP)/(1+alpha))^2/(((1-alpha)P)/(1+alpha))=(alpha^2P)/(1-alpha^2)#

Now inserting

#Q_p=((0.5)^2P)/(1-(0.5)^2)=(P/4)/(1-1/4)=P/3# So

#P=3xxQ_p#

Hence the total pressure of the reaction mixture will be **three times** the reaction quotient at the desired state of 50% dissociation.