The rate of diffusion of methane gas, CH4, is four times the rate of diffusion of an unknown gas under the same conditions of temperature and pressure. What is the molar mass of the unknown gas

How many liters of ethylene glycol antifreeze (c2h6o2), with a density of 1.100 g/l, would you add to your car radiator containing 15.0 kg of water if you needed to protect your engine to - 21.5°c? for water, kf = 1.86°c m -1.