help pls

1. Is diphenylmethane a solid or a liquid at room temperature? 2. What solvent would you use to measure the density of napthalene? 3. Convert your densities to kg/L and compare those values with the ones in g/mL. 4. If air bubbles were trapped in your solid beneath the liquid level in your density determination, what error would result in the volume measurement? What would be the effect of this error on the calculated density? 5. A liquid unknown was found to be insoluble in water and soluble in cyclohexane and alcohol; the unknown was found to have a boiling point of 58C at 670mm Hg. What is the substance? What could you do to confirm your