10 Messrs Paine and Evans, The Conductiunty of ' 
9-0 x 10-* reciprocal ohm. The curve obtained by plotting the 
results is shown in Fig. 5. It is exactly similar to those obtained | 
with the pure water, only the phenomena we are studying are 
shown on a larger scale. Also, dk/dm for the ‘normal’ part of 
the curve is 0°373. 
1:5 
Conductivity (10-4 reciprocal ohm) 
Concentration of H2SO, (10-4 gm.-equiv. per litre) 
Fig. 5. 
(5) We have supposed that ammonia and carbonic acid gas © 
are dissolved in the distilled water from the air, and that on the © 
addition of a strong acid, the hydrogen and carbonate ions combine — 
to form undissociated carbonic acid. Let us suppose that this : 
takes place according to the equation 
mlebre (Oa = = lal(COe 
Let m, and m, represent, respectively, the number of gram- | 
equivalents of H* and CO;~~ ions present in one litre, and mg 
the number of gram-equivalents of undissociated H,CO,. Then | 
when equilibrium is attained we have 
MM, = P. Mz 
Mah Ma 
7 
or 
. * See Note at the end of the Section. 
