A mixture of oxygen and hydrogen is analyzed by passing it over hot copper oxide and through a drying tube. Hydrogen reduces the CuO according to the reaction CuO(s) + H₂(g) → Cu(s) + H₂O(l), and oxygen reoxidizes the copper formed according to Cu(s) + 1/2O₂ (g) → CuO(s). At 25°C and 750. Torr, 172.0 cm³ of the mixture yields 77.5 cm³ of dry oxygen measured at 25°C and 750. Torr after passage over CuO and the drying agent. What is the original composition of the mixture?