What solvent would you use to determine the density of zinc chloride?

You would use cyclohexane

Explanation:

Hi, zinc chloride () is soluble in water or other polar solvents, and the zinc is reactive in solvents with a oxidation potencial.

This is why to determine the density of this salt you need to use a non-polar non-reactive solvent like cyclohexane, so the salt will remain intact and you can measure the volume that it displaced.

Knowing that volume and the weight you can determine the density.