The active ingredient in many commercial antifreezes is ethylene glycol (c6 h6 o2). If you wish to protect your radiator down to -25 degrees F, how many grams of ethylene glycol should you add to each liter of water? First convert the temperature to degrees Celsius, use the Kf vaule of 1.853 degrees C/molal for water, and recall that the density of water is 1.00 g/mL.