乙醚的沸点为308K,50g乙醚中溶解8g萘的溶液在310.80K时沸腾,求乙醚的摩尔沸点升高常数?
问题描述:
乙醚的沸点为308K,50g乙醚中溶解8g萘的溶液在310.80K时沸腾,求乙醚的摩尔沸点升高常数?
答
萘的分子量为128,则其溶液的质量摩尔浓度为:C = (8/128)mol /0.050kg = 1.25mol/kg
(310.8-308) = KbC
Kb = 2.8/1.25 = 2.24