## Chapter 11, Question 7

Miranda 1J
Posts: 51
Joined: Fri Sep 29, 2017 7:06 am

### Chapter 11, Question 7

The following flasks (page 456) show the dissociation of a diatomic molecule, X2, over time.
a) Which flask represents the point in time at which the reaction has reached equilibrium?
b) What percentage of the X2 molecules have decomposed at equilibrium?
c) Assuming that the initial pressure of X2 was 0.10 bar, calculate the value of K for the decomposition.

Thanks:)

Naveed Zaman 1C
Posts: 62
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 2 times

### Re: Chapter 11, Question 7

A) You want to find at what point the amount of the diatomic molecule remains constant. If you look at the 3rd and 4th flask, there is no change in the amount of each substance, so equilibrium is reached by the 3rd flask.

B) 6 out of the 11 original diatomic molecules have decomposed going from the 1st flask to the equilibrium (3rd) flask.

C) The reaction is X2 = 2X

Use mole fraction (#Target atoms/molecules/#All atoms/molecules and multiply it by 0.1, which gives you the relative pressure for each gas at equilibrium. So you get the equation (12/17 X 0.1)2/(12/17 X 0.1), which is just a variation of the equilibrium constant expression.