Process variables and experimental data for two factors, three levels response surface design^a.

Run	A (°C)	B (%)	R 1 (%)	R 2 (h)
1	36	85	0	24
2	100	50	64	0.25
3	62	100	5	24
4	62	50	20	7
5	62	50	26	7
6	62	50	16	7
7	62	50	22	7
8	62	0	47	2
9	36	15	27	24
10	89	15	84	0.5
11	62	50	30	7
12	89	85	5	24
13	25	50	0	24

^a A = temperature (°C), B = water content of aqueous ethanol (%), R₁ = yield of reaction, R₂ = reaction time.