Using the equations Ca (s) + ½ O₂ (g) → CaO (s) ∆H° = -635 kJ/mol
CaO (s) + H₂O (l) → Ca(OH)₂ (s) ∆H° = -64 kJ/mol
2 H₂ (g) + O₂ (g) → 2 H₂O (l) ∆H° = -572 kJ/mol
Determine the enthalpy for the reaction
Ca (s) + 2 H₂O (l) → Ca(OH)₂ (s) + H₂ (g).

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?