Why methyl is poor extraction solvents?

Answer 1

Both are miscible (fully soluble) with water, so you would not be able to form two layers. For extractions and washes, you must use a solvent that is insoluble with water, such as ethyl acetate, dichloromethane, ether, etc.

Answer 2

The polarity, dipole moment, polarizability and hydrogen bonding of a solvent determines what type of compounds it is able to dissolve and with what other solvents or liquid compounds it is miscible. As a rule of thumb, polar solvents dissolve polar compounds best and non-polar solvents dissolve non-polar compounds best: "like dissolves like". Strongly polar compounds like sugars (e.g. sucrose) or ionic compounds, like inorganic salts (e.g. table salt) dissolve only in very polar solvents like water, while strongly non-polar compounds like oils or waxes dissolve only in very non-polar organic solvents like hexane. Similarly, water and hexane (or vinegar and vegetable oil) are not miscible with each other and will quickly separate into two layers even after being shaken well. Ethyl alcohol is a compromise solvent. It dissolves water and oil compounds both, but doesn't do either very well. The polar side of the ethyl molecule is attracted to water (which is the OH- group on the ethyl molecule) but has no affinity for oil compounds. The non-polar side of the ethyl alcohol is attracted to oil compounds but has no affinity for water. So to dissolve an oil compound you need a pure non-polar compound, such as hexane, which has no attraction to water and uses all of its solvating power to dissolve oil compounds. Likewise use water to dissolve sugar or salt. It is much better solvent for that then ethyl alcohol which wastes some solvating power on the non-polar carbon group of the molecule.

Answer 3

I'm assuming you mean methyl alcohol (also called methanol)? Methanol is miscible in both polar (ex water) and non polar (ex dichloromethane or ethyl acetate) solvents. You would get no phase separation. For an extraction to work, you muse use two non-miscible solvents to create two layers (such as water + ethyl acetate).

Answer 4

H3-C-O-+H - looks like roughly half polar and half non-polar: that makes it a very weak non-polar [extraction] solvent.