Here is why this set of equilibrium amounts for A, BC,
AB and C is reasonable.
Guess
|
A
|
BC
|
BC
|
C
|
Reasonable (Y/N)
|
3
|
2.2
|
.8
|
2.8
|
3.8
|
(Yes/No)
|
In this guess the Change (the amounts reacting and forming) can be determined
for A, BC, AB and C by comparing the equilibrium amount
of each species to the initial amount.
For A: [A]equilibrium - [A]initial
= 2.2 - 4.0 = -1.8 (Since the equilibrium amount is less than the initial amount
we include a '-' to indicate is A reacting.)
For BC: [BC]equilibrium - [BC]initial
= 0.8 - 2.6 = -1.8 (Since the equilibrium amount is less than the initial amount
we include a '-' to indicate is BC reacting.)
For AB: [AB]equilibrium - [AB]initial
= 2.8 - 1.0 = +1.8 (Since the equilibrium amount is higher than the initial
amount we include a '+' to indicate is AB forming.)
For C: [C]equilibrium - [C]initial
= 3.8 - 2.0 = +1.8 (Since the equilibrium amount is higher than the initial
amount we include a '+' to indicate is C forming.)
Experiment #7
|
[A]
|
[BC]
|
[BC]
|
[C]
|
Initial
|
4.0
|
2.6
|
1.0
|
2.0
|
Change
|
-1.8
|
-1.8
|
+1.8
|
+1.8
|
Equilibrium
|
2.2
|
0.8
|
2.8
|
3.8
|
The Change does follows the stoichiometry of the balanced chemical equation;
A(g) + BC(g) ---> AB(g)
+ C(g)
One important criteria is the stoichiometry in the chemical equation must
be the same as the stoichiometry of the Change row: 1 A : 1 BC
: 1AB : 1 C. In this case it is.
This is a reasonable guess in terms of the stoichiometry of the reaction.