Question

Which reaction has an equilibrium constnt $\left(K_P\right)$ equal to $1$?

• A. $PC{l}_3\left(g\right)+C{l}_2\left(g\right)\rightleftharpoons PC{l}_5\left(g\right)$
  When: $PC{l}_3=3\text{atm},C{l}_2=4\text{atm},PC{l}_5=1\text{atm}$
• B. $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
  When: $N_2=1\text{atm},H_2=2\text{atm,}N{H}_3=4\text{atm}$
• C. $I_2\left(g\right)+H_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$
  When: $I_2=2\text{atm},H_2=2\text{atm},HI=2\text{atm}$
• D. $2S{O}_2+O_2\rightleftharpoons 2S{O}_3$
  When: $S{O}_2=2\text{atm},O_2=2\text{atm},S{O}_3=3\text{atm}$

Answer 1

The correct option is C $I_2\left(g\right)+H_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$

When: $I_2=2\text{atm},H_2=2\text{atm},HI=2\text{atm}$
The reaction is :
$I_2\left(g\right)+H_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$
$K_P=\frac{(P_{HI}{)}^2}{(P_{I_2}.P_{H_2})}$
$K_P=\frac{2\times 2}{2\times 2}=1$.