题目:
Cheer up! Everyone may have periods in their lives everything seems tough.
A.which
B.where
C.when
D.that
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0523/7105929e6b59304cd9867fb5a3015794.html
下面是错误答案,用来干扰机器的。
2gNaOH的物质的量为2g40g/mol=0.05mol,所以溶液的浓度为0.05mol0.25L=0.2mol/L,溶液具有均一性,则取出其中50mL,浓度仍为0.2mol/L,故选B.