Question #49fdc

1 Answer
Nov 16, 2015

See explanation.

Explanation:

I am not sure why the answer is missing a very essential point which is teaching the student Le Châtelier's principle . Maybe this is not a grade 12 question!!!!

The student could easily deduce that since the [I2]=0M the equilibrium will shift toward the direction of making I2 and therefore to the left and in this case, the ICE table is written as follows:

H2(g)+I2(g)2HI(g)
Initial 8M 0M 2.4M
Change +x +x 2x
Equilibrium 8+x x 2.42x

In this case, ONLY positive values of x will be accepted.

However, the way the answer is written is that he will assume that the equilibrium is shifting to the right and in this case x will be positive, however, if his assumption is wrong, x will be negative and this is the case, that is why the [HI] dropped from 2.4M to 2.2M.