题目

Most middle school students find it boring to learn math . But students in Yat Sen middle school in New York, US, don’t think so. Why? Because they are in the school of One Program, which asks students to work on their own or in small groups on computers to have math lessons. “The program gives the students a new learning style. No traditional classroom can compare with it. We give each lesson according to the students’ interest and their strong and weak points,” said JoelⅠ. Klein, the school’s head teacher, “we’re looking for a new way that interest students children.某实验小组利用图5所示仪器进行“配制质量分数一定的氯化钠溶液”的实验（提示：图7中凹液面与“80”上方两格处相切）（1）图5中仪器a的名称是       ，按实验要求，图5中还缺少的玻璃仪器是（填名称）       ，在实验中该仪器的作用是                           ；（2）完成此实验的正确的操作顺序是（填序号）               ；①溶解，②装瓶贴标签，③称量，④计算（3）马虎同学按图6的操作称取氯化钠，细心同学发现马虎的操作有错误。你认为马虎同学操作中的错误是                             ，他称取的氯化钠实际质量为     g； （4）聪明同学量取蒸馏水的体积如图7所示，则该实验小组原计划配制的氯化钠溶液中溶质质量分数为（水的密度为1g/cm3）         ，图6的错误操作使配得的溶质的质量分数          （填“不变”、“偏大”或“偏小”）。