天气预报15天查询> 其他> 为什么实验中要进行减压过滤

为什么实验中要进行减压过滤

更新时间: 2020-07-03 00:00:00     

有些物质要在一定的大气压下进行实验,所以实验中要进行减压过滤 。减压过滤可加速过滤,并使沉淀抽吸得较干燥,但不宜过滤胶状沉淀和颗粒太小的沉淀,因为胶状沉淀易穿透滤纸,沉淀颗粒太小易在滤纸上形成一层密实的沉淀,溶液不易透过。循环水真空泵使吸滤瓶内减压,由于瓶内与布氏漏斗液面上形成压力差,因而加快了过滤速率,布氏漏斗上有许多小孔,滤纸应剪成比漏斗的内径略小,但又能把瓷孔全部盖没的大小。用少量水润湿滤纸,开泵,减压使滤纸与漏斗贴紧,然后开始过滤。当停止吸滤时,需先拔掉连接吸滤瓶和泵的橡皮管,再关泵,以防反

关键词: 为什么 实验 进行 减压 过滤

如有意见、反馈、侵权或投诉等情况,请联系:

电话:
邮箱:

我们将会在48小时内给与处理!

版权所有 Copyright ? 2009-2020 tianqiyubao3.com

页面:/news/view-1524968/ | 耗时:0.2470 s | 内存:1.89 MB | 查询:4 | 缓存读取:4 写入:0 | 加载文件:23
select * from tbl_Articles WHERE ArticleID=1524968 LIMIT 0,1
select * from tbl_Articles_data WHERE ArticleID=1524968 LIMIT 0,1
select * from tbl_Articles_sphinx where id=1524968 LIMIT 0,1
SELECT ArticleID,Title FROM tbl_Articles WHERE ArticleID IN(542075,1107329,1464268,1833272,1298039,1102443,427322,1994506,1093192,1088475,2007970,1061782,1492486,2480306,1349234,1788397,1097767,1098434,2481856,2036361,2321834,1809106,1092422,1089464,1112032,1046963,1120324,1894368,2229462,1089526) ORDER BY field (ArticleID,542075,1107329,1464268,1833272,1298039,1102443,427322,1994506,1093192,1088475,2007970,1061782,1492486,2480306,1349234,1788397,1097767,1098434,2481856,2036361,2321834,1809106,1092422,1089464,1112032,1046963,1120324,1894368,2229462,1089526)