# will two weak acids lower their degree of dissociation when put together in solution compared to when put separately

When two weak acids are put in aqueous solutions separately they will have some value of degree of dissociation, now when both are put together will there be a decrease in their dissociations, I think they should lower each other dissociation due to common ion effect (H+ from both) , the problem is that in my textbook they give resultant H+ion concentration by adding individual concentration , those values being same as if when put in separately .. can anyone please explain me what's correct mathematically ?

• You are correct. Obviously the acid with the smaller pKa would contribute more to the H+ concentration than the other acid, but the other acid would contribute some too. – MaxW Jan 15 at 20:56
• Thanks , atleast I know that I was correct , but how to calculate the new degrees of dissociation ? when we take suppose a weak acid with a strong one , I can calculate degree of dissociation by assuming that conc. of h+from strong acid part I constant (strong acid ) but I cannot do it here , because both are depreciating each others dissociation – Nutan Prakash Jan 16 at 2:57