In: Chemistry
During the dehydration experiment, C2H4(g) and unreacted C2H5OH(g) passed through the tube into the water. The C2H4 was quantitatively collected as a gas, but the unreacted C2H5OH was not. Explain this observation in terms of the intermolecular forces between water and each of the two gases.
1)Water is highly polar solvent and capable of forming strong Hydrogen bonding.
2)Dehydration of alcohol Ethanol forms unsaturated hydrocarbon ethene(H2C=CH2) compound and it’s a non-polar molecule and not capable of forming Hydrogen bonding with water.
3)Alcohol i.e. ethanol can form strong hydrogen bonding with water.
4)Due to hydrophobic repulsive kind of interaction ethene gas remained isolated from water i.e.do not dissolve in water and hence collected as gas quantitatively.
5)But (unreacted) ethanol gas being able to form extensive Hydrogen bonding with water get dissolved in water (At normal temperature ethanol is in liquid form but as dehydration carried out must be elevated temperature used). That is why we unreacted ethanol is not collected quantitatively.
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