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一、考查化学实验的基本操作例1(上海)下列实验基本操作错误的是()(A)滴定管洗净后经蒸馏水润洗,即可注入标准液进行滴定(B)玻璃导管蘸水后,边旋转边向橡皮管中插入(C)加热坩埚中的硫酸铜晶体。失水后须在干燥器中冷却,再称量(D)玻璃棒蘸取溶液滴到放在表面皿上的pH试纸上解析:因滴定管洗净后经蒸馏水润洗,再经标准液润洗,才可注入标准液进行滴定;而(B)、(C)、(D)实验基本操作正确,故正确答
First, examine the basic operation of the chemical experiment Example 1 (Shanghai) The following basic operation of the experiment is wrong () (A) After rinsing the tube washed with distilled water rinse, you can inject the standard solution for titration (B) glass catheter drowning, Insert (C) the copper sulfate crystals in the crucible while rotating the tube. After dehydration, it shall be cooled in a desiccator, and then weighed. (D) The glass rod dipping solution shall be dripped on the pH paper on the watch glass. Analytical solution: After rinsing, rinse with distilled water and rinse with standard solution. Only the standard solution can be injected for titration; but the basic operation of (B), (C), (D) is correct, so the correct answer