How would decreasing the pressure affect the equilibrium of this reaction? Hat 12 32H1 O A. The reaction would remain in equilibrium B. HI would react to produce more H2 and 12 more quickly. O C. H2 and 12 would react to produce HI more quickly. D. All of the molecules would react more slowly.

A. The reaction would remain in equilibrium

Given

Reaction

H₂ + I₂ ⇔ 2HI

Required

the effect of pressure changes

Solution

In the equilibrium system :

Reaction = - action  

⇒shift the reaction to the right or left.  

The pressure usually affects the gas equilibrium system(only count the number of moles of gases)

The addition of pressure, the reaction will shift towards a smaller reaction coefficient  ((the fewest moles of gas  )

Reaction

H₂ + I₂ ⇔ 2HI

The reactant side of the equation has 2 moles of a gas(1 mole H₂ and 1 mole  I₂) ; the product side has 2 moles HI

So the total number of moles from both sides is the same(2 moles) so that the change in volume (pressure) does not change the direction of equilibrium⇒No shift will occur

12 is it do you think so