Chemical equilibrium ( equilibrium constant (k))

[ZEUS11111111]

If the value of K for a certain reaction at equilibrium is greater than 1 then can we say that the concentration of product is more dominant than the concentration of reactants at equilibrium state?

[studiot]

48 minutes ago, ZEUS11111111 said:

If the value of K for a certain reaction at equilibrium is greater than 1 then can we say that the concentration of product is more dominant than the concentration of reactants at equilibrium state?

 

Firstly welcome Zeusetc.

Is this a homework question  -  it looks rather like one, except that you are not specific enough ?

What do you mean by the concentration of the product (in the singular) and the concentration (again in the singular) of the reactants (in the plural ?

 

Have you heard of addition or condensation reactions ?

Edited April 21, 2021 by studiot

[ZEUS11111111]

I meant to say the collective concentration of both products and reactants.

 

[studiot]

55 minutes ago, ZEUS11111111 said:

I meant to say the collective concentration of both products and reactants.

 

That's even less clear.

Say you have a reaction

[math]A + C \leftrightarrow D[/math]

 

or

[math]A \leftrightarrow C + D[/math]

 

What difference does the concentrations [A] ; [C] ; [D]  make to K  ?

 

You haven't answered my question is this homework ?

Edited April 21, 2021 by studiot

[ZEUS11111111]

No it is not a homework . 

 

What i meant to say is since K is the ratio of product of concentration of products raised to the power of their stoichiometric coefficient and product of concentration of reactants raised to their power of their stoichiometric coefficient , in the case of A + C = D , K = [D]/[A][C] and if this value of K > 1 can we say that the concentration of D is more dominant than the concentration of the two products combined .

 

 

[studiot]

13 hours ago, ZEUS11111111 said:

No it is not a homework . 

 

What i meant to say is since K is the ratio of product of concentration of products raised to the power of their stoichiometric coefficient and product of concentration of reactants raised to their power of their stoichiometric coefficient , in the case of A + C = D , K = [D]/[A][C] and if this value of K > 1 can we say that the concentration of D is more dominant than the concentration of the two products combined .

 

 

How can the concentration be dominant ?

The value of K is only one of several (simultaneous) equations that a chemical reaction must satisfy.

So to take the case of in the case of A + C = D , K = [D]/[A][C] again, what does the reaction equation say ?

The reaction equation ( A + C = D)  says that for every molecule or gram-mole of D created two molecules or gram moles (one of A and one of C) are removed when the reaction reaches equilibrium.

But we do not have to start in equilibrium (or there would be no reaction).

So we could start with quite different concentrations of A and C, say 1M for A and 0.1M for C.

Initially we have

[A] = 1.0 ; [C] = 0.1; [D] = 0 

so the total quantity of reactantants = 1.1 mole/L  and of products  = 0 mole/L

In that case the reaction could not reduce the concentration of A below (1.0 -0.1) = 0.9 mole/L because at that point it would run out of C.
At that point we would have

[A] = 0.9 ; [C] = 0; [D] = 0.1

So now we have a total of 0.9 mole/L of reactants and 0.1 mole/L of products, making a grand total of 1.0 mole/L

ie a reduction.

 

Perhaps you would like to consider the implications of what happens if K is 0.9,, 1.0 and 1.1 respectively ?

Edited April 22, 2021 by studiot