题目

下列是关于盐酸滴定氢氧化钠溶液的实验叙述:①取一锥形瓶用待测NaOH溶液润洗两次;②在锥形瓶中放入25.00mL待测液;③加入几滴石蕊试剂滴至刚变紫色立即停止;④取一只酸式滴定管,洗涤干净;⑤不润洗滴定管,直接往其中注入标准酸溶液,进行滴定;⑥左手旋转滴定管的玻璃活塞,右手不停摇动锥形瓶;⑦两眼注视滴定管内盐酸溶液液面下降,直至滴定终点。其中操作错误是A. ④⑥⑦         B. ①⑤⑥⑦        C. ③⑤⑦       Ideally______for Broadway theatres and Firth Avenue, the AVw York Park hotel is n favounte with many guests. A. locating                         B. being located               C. having been located  D. located
化学 试题推荐