posted by Katherine on .
Calculate the concentrations of all species in a 0.810 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4 x 10^-2 and Ka2 = 6.3 x 10^-8
I calculated SO32- = 0.8096 M, HSO3- = 3.58E-4, H2SO3 = 7.1E-13, OH- = 3.58E-4, H+ = 2.79E-11
but i keep getting Na+ wrong!!! please help!
I think I answered this late last night that Na^+ = 2 x 0.810M = ?
Is that not right?
Ohh.. I didn't know you were supposed to multiply the SO32- concentration by 2 for Na... That's right thanks DrBob!
Na2SO3 is 100% dissociated; therefore, Na2SO3 ==> 2Na^+ + SO3^2-
So if Na2SO3 is 0.810M than Na^+ is twice that. You are multiplying the Na2SO3 by 2; not multiplying SO3^2- by 2. The SO3^2- is not 0.810 since it hydrolyzes (at least to a slight extent).
What was your second chemical equation that you used?
If you have a question it would be best to post it under "Post a new question."