Question

Predict whether each of the following solvents is miscible or immiscible with water.

ethanol C2H5OH
toluene C7H8
trichloroethylene C2HCl3
acetic acid CH3COOH

Please show work on how to determine miscibility. And determining how it is polar or non-polar.

Thank you

Answer 1

Like dissolves like is the principle. Water is highly polar solvent and polar substance & those are capable of forming Hydrogen bonds with water will be miscible with water and hydrocarbons which re non-polar will be immiscible.

On the basis of this we have following answers:

i) Ethanol C2H5OH : MISCIBLE

Ethanol is polar substance due to C-O and O-H polar bonds. Due to presence of O-H it can form H-bonds with water and there by solubility enhanced.

ii) Toluene C7H8 : IMMISCIBLE

Toluene is a aromatic hydrocarbon and is very non-polar substance.

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iii) trichloroethylene C2HCl3  MISCIBLE

Trichloroethylene is having some finite non-zero dipole moment and hence will be water Miscible to some extent

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iv) Acetic acid CH₃COOH MISCIBLE

-COOH is very polar functional group and capable of forming H-bond and hence is water miscible.

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