Table 5. Equilibrium Solubilities of the Ternary System NaOH–Na₂SO₄–H₂O at T = 363.15 K and P = 88.94 kPa^a.

	composition of liquid phase, w(B) × 100b, %			composition of wet residue, w(B) × 100b, %
no.	NaOH	Na2SO4	H2O	NaOH	Na2SO4	H2O	solution density ρ/g·cm–3	equilibrium phase solidsc
1	0.00	29.91	70.09	0.00	32.01	67.99	1.1984	S
2	6.47	22.86	70.67	4.69	46.87	48.44	1.2158	S
3	10.95	16.25	72.80	4.67	65.08	30.25	1.2034	S
4	14.79	12.41	72.80	7.99	52.67	39.34	1.1965	S
5	17.12	9.65	73.23	9.99	46.34	43.67	1.1990	S
6	20.84	6.07	73.09	14.52	35.32	50.16	1.2146	S
7	25.44	4.97	69.59	16.99	36.12	46.89	1.2522	S
8	30.24	2.49	67.27	22.30	27.86	49.84	1.2930	S
9(E1)	34.18	2.22	63.60	22.61	35.85	41.54	1.3321	S + S1
10	37.39	2.49	60.12	31.93	17.68	50.39	1.3657	S1
11	37.74	2.31	59.95	37.51	29.70	32.79	1.3686	S1
12	41.63	1.66	56.71	40.63	28.33	31.04	1.4048	S1
13	43.74	2.22	54.04	41.87	22.41	35.72	1.4279	S1
14	63.39	2.49	34.12	54.67	23.27	22.06	1.5884	S1
15(E2)	71.62	2.75	25.63	68.31	8.14	23.55	1.5884	S1 + OH
16	76.28	0.00	23.72	72.26	6.81	20.93	1.5884	OH

^aStandard uncertainties u are u(T) = 0.1 K, u(P) = 0.5 kPa, and u_r(Na₂SO₄) = u_r(NaOH) = 0.05.

^bw(B) is the mass fraction of the component (B).

^cAbbreviations: S, Na₂SO₄; OH, NaOH; and S1, Na₂SO₄·NaOH.