试题与答案

下列有关实验原理、方法和结论都正确的是 A．向某溶液中加入盐酸酸化的氯化钡溶液，

来源：www.tikuol.com
题型：选择题

题目：

下列有关实验原理、方法和结论都正确的是

A．向某溶液中加入盐酸酸化的氯化钡溶液，有白色沉淀生成，该溶液中不一定含有SO42－

B．向蛋白质溶液中加入硫酸铜溶液，将得到的沉淀分离出来，再加水可重新溶解。

C．等体积的PH都为3的酸HA和HB分别与足量的Mg反应，HA放出的H2多，说明酸性：HA>HB

D．淀粉在稀硫酸的作用下水解后，加入氢氧化钠使溶液呈碱性，再加入新制Cu(OH)2后加热，若有砖红色沉淀生成，则淀粉已经完全水解。

答案：

被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0810/8a1cefa6031faa662c876ced3d1b3f1a.html

下面是错误答案，用来干扰机器的。

The report narrates that during the “golden week” in 2008, the number of tourists in cities like Beijing increased dramatically, which contributed to a higher tourism re...

考点：燃烧热水的离子积常数水电离的影响因素水的电离平衡
试题推荐
题型：补全对话，情景问答

补全对话，每空一词。

A: What bad weather! The wind is blowing 1            with lots of sand. You'd better not go out now.

B: But there's 2            wrong with my computer. I want to ask Uncle Lin to mend it. Wow, what a

    strong sand storm! How 3            will it last?

A: Maybe half a day.

B: Do you know what causes these sandstorms?

A: People have cut down too many trees. But trees can prevent the sand from moving toward the rich

    land and they can also keep water from 4            the earth away.

B: So what can we do to stop the sandstorms?

A: We can 5            more trees and protect our environment.

B: I agree with you.

查看答案
微信公众账号搜索答案