Answer to Question #156051 in General Chemistry for Crystal

Question

Intermolecular Forces

1.     Try to dissolve a crystal of NaCl and a small flake of naphthalene/menthol crystal in 1 cm³ of each of the following solvents commonly found in the home; kerosene, ethanol (rubbing alcohol/methylated spirits), acetone (nail polish remover) and water.

State whether the solids are insoluble, sparingly soluble, soluble or very soluble in each of the solvents.

2.     Determine whether the solvents mix with one another. Use no more than 1 cm³ liquid. Just state whether miscible or immiscible.

Use your observation from 1 and 2 above, identify the dominant intermolecular forces for each mixture.

Answer 1

As we know, ionic solutes dissolve well in ionic solvents. Similar trend is followed by the covalent solutes and solvents.

Common salt is completely soluble in water, sparingly soluble in ethanol, insoluble in acetone and kerosene, While Naphthalene is completely soluble in kerosene and acetone, soluble in ethanol and insoluble in water.

Kerosene is immiscible in water, while ethanol and acetone are miscible in water.

For highly polarised covalent- covalent mixture or covalent - ionic mixture, hydrogen bonding is the inter molecular forces that are dominant, while for non polarised or negligible polarised covalent - covalent mixture, London dispersion forces dominate the inter molecular interactions.