Dilution and Additon of Reactants

[kenhung123]

When a reaction in equilibrium contain the reactant water, when diluted, how do we know whether the conc of product increase or decrease? Because the reaction would shift to the right but then at the same time its diluted

[Martoman]

It will move to the side of greater particles. If that happens to be the product side, then it increases.

[kenhung123]

Your saying shift+dilution=overall increase in the conc of products

[Martoman]

You dilute something. The system will partially oppose the change. It can never get to the same concentration as before.

[stonecold]

what if the number of particles are the same for both reactants and products?

[kenhung123]

You dilute something. The system will partially oppose the change. It can never get to the same concentration as before.

Hmm..not sure if you get what I am saying.
E.g. HA + H2O <=> H2A+ + OH-

So if I add H2O, I am diluting but at the same time adding more reactants. By LCP, it would shift to the right therefore increase [products] but then I am diluting the entire solution. So is the resultant solution greater or less than initially?

[98.40_for_sure]

You dilute something. The system will partially oppose the change. It can never get to the same concentration as before.

Hmm..not sure if you get what I am saying.
E.g. HA + H2O <=> H2A+ + OH-

So if I add H2O, I am diluting but at the same time adding more reactants. By LCP, it would shift to the right therefore increase [products] but then I am diluting the entire solution. So is the resultant solution greater or less than initially?

In terms of concentration, resultant solution is LESS (note: 'partially' oppose). In terms of no. of moles, it goes UP, as dilution does not change number of moles. Your question is ambiguous. By the way, H2O is not included in the Ka equation. Thus you are not "adding reactants", you're merely diluting it, so it goes from 1 -> 2 particles. I'm not 100% sure but all (s) and (l) states are not included in Ka equations (i dunno about the liquid, but solid isn't because any solid's conc is 1)

[qshyrn]

what if the number of particles are the same for both reactants and products?

nothing happens. you can prove this mathematically using calculation for K, youll see that the volume (and hence conc.) can be anything and K will not change

[physics]

its decreasing the concentration...so u can do the rest