3. Unknown compound C is thought to be either dimethyl ether, diethyl ether, or di-isopropyl ether, whose formulas are $C_2H_6O$, $C_4H_{10}O$, and $C_6H_{14}O$, respectively. A glass bulb filled with vaporized compound C at 75.3°C and 743 mm Hg pressure, weighed 177.11 g. Evacuated, the glass bulb weighed 176.41 g; completely filled with water, the glass bulb weighed 452.12 g. Determine the identity of compound C. (3 points) Assume a density of 0.9978 g/cm³ for the water used in the calibration of the glass bulb.