1 If the invitation says black tie, women should wear a floor-length, evening gown. 2  A tuxedo is mandatory if you're a man. 3  This is your chance to dress as if you were headed to the Oscars. 4  Black tie optional means that wearing a tuxedo or long evening gown is not mandatory, but guests should feel free to do so.
Ether is an organic functional group consisting of a disubstituted oxygen, or an oxygen atom bonded to 2 carbon atoms (if adjacent to a ketone, functional group is then called an ester).
Water is polar in nature while Ether is non-polar. Ethers are very slightly soluble in water at around 6.8g/100g. This is due to the presence of oxygen in ethers which interact with hydrogen in water to produce H-bonding to make it slightly soluble. And this low solubility is what makes a two-phase mixture of water and ether excellent for separation techniques.