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

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

anonymous · Answer

I'm not sure if this is proper, but you could go through each and see if it adds up... for (A) we have $x$ moles of R, and thus $2-x$ moles of $P$ and $2x$ moles of Q. This adds up to $2+2x$, though. If you go through them, you find the only consistent one is (D); we have $x$ moles of R, $2-x$ moles of P, and $\dfrac{x}2$ moles of Q -- this sums to $2+\dfrac{x}2$ as expected.