4. An impatient student does not wait for all the iodine to react. Subsequently, the remaining iodine sublimes away during the product isolation step. Will the calculated mass ratio for the product, g I/g Zn, to be higher or lower than the correct value? Explain.

Higher

Explanation:

It looks as if you prepared zinc iodide by the reaction of zinc with iodine.

Your procedure was probably something like this:

You know the mass of iodine used, so you can get the mass of zinc by difference.

For example, assume you measured out 0.5 g of I₂ and got 0.6 g of ZnI₂ as product. You would assume it contained 0.5 g of I₂ and 0.1 g of Zn. Your calculated mass ratio would be I₂/Zn = 5/1.

The impatient student loses 0.1 g of I₂ by sublimation, so they get only 0.55 g of ZnI₂. However, they still think it contains the original 0.5 g of I₂, and they determine the mass of Zn to be 0.05 g. Their calculated mass ratio is I₂/Zn = 0.5/0.05 = 10/1.

If some of the iodine sublimes away, the calculated value for the mass ratio will be higher than the correct value.

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.