Question

EQUILIBRIUM Two moles of compound P were placed in a vessel. The vessel was heated and compound P was partially decomposed to produce Q and R. A dynamic equilibrium between chemicals P,Q and R was established. At equilibrium x moles of R were present and the total number of moles present was (2+x/2). What is the equation for this equilibrium reaction? A) P <-> 2Q+R B) 2P <-> 2Q+R C) 2P <-> Q+R D) 2P <-> Q+2R

Answer 1

As given:

Initial moles of P taken = 2 mol

the products are R and Q

at equilibrium the moles of

R = x

total moles =  2 + x/2

Let us check for each reaction

A) P <-> 2Q+R

Here if x moles of P gets decomposed it will give 2x moles of Q and x moles of R

So at equilibrium

moles of P left = 2- x

moles of Q = 2x

moles of R = x

Total moles = (2-x) + 2x + x = 2 +2x

B) 2P <-> 2Q+R

Here x moles of P will give x moles of Q and x/2 moles of R

So at equilibrium

moles of P left = 2- x

moles of Q = x

moles of R = x/2

Total moles = (2-x) + x + x/2 = 2 + x/2

C) 2P <-> Q+R

Here x moles of P will give x/2 moles of Q and x/2 moles of R

So at equilibrium

moles of P left = 2- x

moles of Q = x /2

moles of R = x/2

Total moles = (2-x) + x + x = 2

D) 2P <-> Q+2R

Here x moles of P will give x/2 moles of Q and x moles of R

So at equilibrium

moles of P left = 2-x

moles of Q = x/2

moles of R = x

Total moles = (2-x) + x/2 + x = 2 + x/2