JEE Main 2014 · 9 Apr · Shift 1 · Chemistry Q34

ChemistrySingle correct+4 / -1Question 34 of 90

At a certain temperature, only 50% HI is dissociated into $\ce{H2}$ and $\ce{I2}$ at equilibrium. The equilibrium constant is :

1.0

3.0

0.5

0.25

Answer and worked solution

Official answer: D

For $\ce{2HI <=> H2 + I2}$ , starting with 1 mol HI, half dissociates: HI 0.5, $\ce{H2}$ 0.25, $\ce{I2}$ 0.25.
$K=\frac{0.25\times0.25}{0.5^2}=0.25.$

JEE Main 2014 · 9 Apr · Shift 1, Chemistry question 34