what type of the following solvents might be used to dissolve an oil stain?

water, diethyl ether, NaCl solution, CCl4, benzene

Thanks
Thank you so much Dr. buzz. You save my life. That answers is correct.

Identify the classes of the following compounds?

CH3CH2CH2CH2COOH- Pentanoic Acid is a member of the amino acids class.
CH3CH -> <- CHCH2CH3- 2-Pentene is a member of the secondary alcohol class.
C2H5OC2H5- Diethyl ether is a member of the ether class.
CH3CH2CHOHCH2CH3- 3- Pentanol is a member of the primary alcohol class and is an organic compound.
(CH3)3 COH- 2-Propanol is a member of the secondary alcohol class and is also an organic compound.
CH3║CH is a member of the carboxylic acid class
I just want to check if I have this right, especially the last one. Thanks for the help!

How do you do this chemistry lab problem?

The equation relating approximate barometric pressure (P, in torr) to altitude(h, in m) is at room T:

lnP = 6.63-(h8000)

Diethyl ether, CH3CH2OCH2CH3, a common organic solvent has a normal boiling point at 34.6 degrees C (and thus vapor pressure of 760 torr at 34.6 C). at 20 degrees C, it has a vapor pressure of 440 torr. At what approximate altitude will diethyl ether boil at 20 C? Where on the earth would it be a problem to keep this solvent liquid?