Why does Bill spend a lot of time to study English?
A. Because he is interested in English
Because he's apply for a job in an international company.
查看答案
Is English a must for the job?
A. Yes, it is.
B. No, it isn't
分光光度法中不影响摩尔吸光系数的是( )
A. 溶液温度
B. 入射光波长
C. 液层的厚度
D. 物质的特性
硫酸铜溶液显蓝色是由于它吸收了白光中的( )
A. 绿光
B. 蓝光
C. 黄光
D. 紫光
以邻二氮菲光度法测定Fe(II),称取试样0.500克,经处理后,加入显色剂,最后定容为50.0mL,用1.0cm吸收池在510nm波长下测得吸光度A=0.430,试样中铁的百分含量为____。(ε545=1.1×104 L.mol-1.cm-1)
A. 0.22%
B. 0.022%
C. 2.2%
D. 0.0022