Assuming that the nacl is completely ionized, calculate how much it will lower the solute potential of the soil at 20°c using the solute potential equation: ѱs = –icrt where i is the ionization constant (2 for nacl), c is the molar concentration (in mol/l), r is the pressure constant [r = 0.00831 l • mpa/(mol • k)], and t is the temperature in kelvin (273 + °c). how much will the solute potential of the soil be lowered at 20°c?