Equilibrium Concentration Calculations?

[Daniela_Chem14A]

Professor Lavelle went over a problem in class referring to ATP Hydrolysis. When we got our answer for the problem we got that ADP and P were equal to each other. My question is if the ratio of ADP and P were different rather than 1:1, would you have to multiply the different ratio to the value calculated to get what fraction of the value equals ADP and what fraction of the value equals P?

Thank you

[Sarah_Wilen]

Exactly, if you were to have 2 ADP and 3 P produced, you would multiply the # for ADP by 2 and P by 3. Here's an example, see if you can try it:

A mixture consisting initially of 3.00 moles NH3, 2.00 moles of N2, and 5.00 moles of H2, in a 5.00 L container was heated to 900 K, and allowed to reach equilibrium. Determine the equilibrium concentration for each species present in the equilibrium mixture.

2 NH3(g) <--> N2(g) + 3 H2(g) Kc = 0.0076 @ 900 K

The answer is:
[N2]=.184 M
[H2]=.352 M
[NH3]=1.032 M