Question

# For the reaction   2HI(g) ⇌H2(g)+I2(g), Kc= 0.290   at 400 K. If the initial concentration of  HI ...

For the reaction   2HI(g) ⇌H2(g)+I2(g), Kc= 0.290   at 400 K. If the initial concentration of  HI  is  4.0×10−3M and the initial concentrations of  H2, and the initial concentrations of  H2, and I2 are both  1.50×10–3M  at  400 K, which one of the following statements is correct?

a. The concentrations of HI and I2 will increase as the system is approaching equilibrium.

b. The concentrations of H2 and I2 will increase as the system is approaching equilibrium.

c. The system is at equilibrium.

d. The concentrations of H2 and HI will decrease as the system is approaching equilibrium

e. The concentration of HI will increase as the system is approaching equilibrium.

correct statement :

a) The concentrations of HI and I2 will increase as the system is approaching equilibrium.

2HI(g)   <---------------> H2 (g)    +      I2 (g),

4.0 x 10^-3                   1.50x 10^-3    1.50x 10^-3

Kc = 0.290 M

Qc = [H2][I2] / [HI]^2

= ( 1.50x 10^-3 )^2 / (4.0x 10^-3)

Qc = 5.625 x 10^-4

Kc = 0.290

here Kc > Qc.

so the reaction shifts forward direction.

so the concentration of H2 and I2 increases. and HI decreases.

#### Earn Coins

Coins can be redeemed for fabulous gifts.