05/17/2005 - Updated 09:45 AM ET. Long-term weather outlooks. In general, meteorologists do not consider day-to-day forecasts for more than a week or 10 days ahead to be possible, and the best forecasts are for five days or less into the future.n general, meteorologists do not consider day-to-day forecasts for more than a week or 10 days ahead to be possible, and the best forecasts are for five days or less into the future.
This phenomenon is referred to as freezing point depression. The mathematical equation describing freezing point depression is: Î´T = (Kf)(m). Î´T represents the freezing point depression: Î´T = Tfo-Tf. Tfo is the freezing point of the pure solvent. Tf is the freezing point of the solution. Kf is the molal freezing point depression constant, which has a characteristic value for a given solvent. The units of Kf are given in oC/m. is the molality of the solution.
In particular, molality is used when you: determine boiling point; determine melting point; work with colligative properties (boiling point elevation, freezing point depression) Use molality any time you expect the solute may interact with the solute. Use molarity for dilute aqueous solutions held at a constant temperature.