题目

阅读理解Cyclist Alain Such has been dropped from the Ingotel cycling team for two years after a positive drug test at the Institute of drug Free Sport. “ I was flabbergasted.” Said Didier Garcia, from Team Ingotel. “Alain joined our team last month and we had no idea that he was being examined.”It's a story that has become more and more familiar in recent years. Dr. Mohammad Farnood, a leading sports scientist from Cairo, Egypt, said, “ It is thought that some athletes will look for other ways to improve performance in addition to using drugs.”However, it has not always been ag实验小组在检验碳酸钠和氯化钠组成的混合物成分时，他们称取32.8g该混合物放入大烧杯中加蒸馏水溶解得到64g溶液，向该溶液中逐渐加入氯化钙溶液使其充分反应后，过滤、称量，其生成沉淀的总质量与滴入氯化钙溶液的质量关系如图所示．请根据题意回答：（1）原固体混合物中碳酸钠的质量是 ．（2）恰好完全反应时烧杯中溶液的质量分数．