443 
1909-10.] Equilibrium in a Ternary System. 
of potassium carbonate present, the fact that the colour of phenolphthalein 
disappears when the potassium carbonate is changed to bicarbonate was 
made use of. A weighed quantity of solution was therefore titrated with 
an acid of known strength, phenolphthalein being used as indicator, and 
the percentage of potassium carbonate obtained. In order to check these 
results, in most cases the total potassium was determined gravimetrically. 
The results obtained were concordant. 
A series of mixtures were made up as follows : — 
No. of 
Mixture. 
Weight of 
KEt. Salt (gms.). 
Weight of 
K 2 C0 3 (gms.). 
Weight of 
Water (gms.). 
1 
3-081 
3-081 
5-115 
2 
3-011 
3-010 
6*025 
3 
1-953 
4-333 
9-210 
4 
3-059 
3-048 
8458 
5 
3-058 
3-143 
9-654 
6 
3-017 
3-125 
10-673 
7 
3-027 
3-203 
12 032 
unkn 
own. 
Nos. 1, 2, 4, 5, 6 and 7 were made up by taking approximately equal 
weights of the two salts. No. 3 was made up by taking totally different 
proportions of the salts, while the last two mixtures were obtained by 
diluting two of the more concentrated with water to nearly the point at 
which complete mixture took place. 
The solutions were analysed, after equilibrium had been attained, by the 
methods explained above, with the following results : — 
No. of 
Mixture. 
Upper Layer. 
Lower Layer. 
Per Cent. 
Per Cent. 
Per cent. 
Per Cent. 
Per Cent. 
Per cent. 
KEt. Salt. 
k 2 co 3 . 
H 2 0. 
KEt. Salt. 
K 2 C0 3 . 
H 2 0. 
1 
65-1 
4-05 
30-85 
0-4 
42-6 
57-0 
2 
59-8 
4-9 
35-3 
0-4 
40-7 
58-9 
3 
53*5 
5*6 
40-9 
0-5 
35-0 
64-5 
4 
50-5 
7-2 
42-3 
0-9 
33*5 
65-6 
5 
39-2 
8-7 
521 
0-7 
28-9 
70-4 
6 
34-6 
11-0 
54-4 
0-8 
26-8 
72-4 
7 
23-5 
14-5 
62*0 
3-0 
24-8 
72-2 
8 
18-6 
17-0 
64-4 
6-05 
23-1 
70-85 
9 
15-0 
18-6 
66-4 
8-7 
21-7 
69-6 
As will be seen from the above table, even in the case of concentrated 
solutions there is a considerable quantity of potassium carbonate in the 
