问题:氧化还原滴定法采用的指示剂可分为()、()和()三类。...
Sunday, September 11, 2022
Saturday, September 17, 2022
问题:我国标准分为国家标准、专业标准、地方标准和企业标准四级。...
Saturday, September 17, 2022
问题:测定丙烯腈中Fe含量时,邻菲罗啉与铁的显色反应在()进行。...
Tuesday, September 13, 2022
问题:磷钼兰高速比色法测定钢铁中P含量时,加入氟化钠的目的是络合铁、减...
Sunday, September 11, 2022
Saturday, September 17, 2022
Tuesday, September 13, 2022
问题:氧化还原滴定法在化验室的化学分析中应用广泛,如对锰铁中锰含量的分...
Saturday, September 17, 2022
问题:纯的锌粒和稀酸反应很慢,但滴加一些硫酸铜溶液后,反应大大加快。为...
Saturday, September 17, 2022
Tuesday, September 13, 2022
Tuesday, September 13, 2022
问题:甲酸的Ka=1.8×10-4,碳酸的Ka1=4.2×10-7,甲酸的酸性()碳酸的酸性。A、大于B、等于C、小于D、接近...
Friday, June 7, 2024
问题:现工段中控样品需要留样()天, 成品样需保留()年。...
Saturday, September 10, 2022
Saturday, September 17, 2022
Saturday, September 17, 2022
Tuesday, September 13, 2022
Tuesday, September 13, 2022
Saturday, September 17, 2022
问题:称量形式必须具有确定的化学组成并与化学式完全相同。...
Saturday, September 17, 2022
问题:配制碘标准溶液,应该保存在()。A、白色瓶中B、棕色瓶中,暗处C、阴暗处...
Tuesday, July 18, 2023