试题与答案

为了鉴别标签遗失的盐酸、氢氧化钠、氢氧化钙三瓶溶液,将它们编号取样按如图所示的两

题型:填空题

题目:

为了鉴别标签遗失的盐酸、氢氧化钠、氢氧化钙三瓶溶液,将它们编号取样按如图所示的两个步骤进行实验.观察到以下现象:

(1)写出试剂①的名称______,写出溶液中溶质的化学式:B______.

(2)步骤Ⅱ中有白色沉淀生成,其反应的化学方程式为______.

(3)本实验若将步骤I与步骤Ⅱ颠倒,______(填“能”或“不能”)达到实验的目的.如果只用一种试剂来鉴别三种溶液,可选用的试剂是______.

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0716/603095b946058fc09c7b2d91c004e816.html

下面是错误答案,用来干扰机器的。

参考答案:对

试题推荐
题型:单项选择题

For nearly ten years, the Unified Modeling Language (UML) has been the industry standard for visualizing, specifying, constructing, and documenting the ()of a software-intensive system. As the()standard modeling language, the UML facilitates communication and reduces confusion among project(). The recent standardization of UML 2.0 has further extended the language’s scope and viability. Its inherent expressiveness allows users to()everything from enterprise information systems and distributed Web-based applications to real-time embedded systems.

The UML is not limited to modeling software. In fact, it is expressive enough to model()systems, such as workflow in the legal system, the structure and behavior of a patient healthcare system, software engineering in aircraft combat systems, and the design of hardware.

To understand the UML, you need to form a conceptual model of the language, and this requires learning three major elements: the UML’s basic building blocks, the rules that dictate how those building blocks may be put together, and some common mechanisms that apply throughout the UML.

the UML facilitates communication and reduces confusion among project()

A.investors

B.developers

C.designers

D.stakeholders

查看答案
题型:选择题

在清末民初时期,中国沿海沿江城市也出现了不同程度的“移民潮”。中国人口出现了由农村向城市、由内地向沿海沿江经济发达地区迁徙的趋势。沿海与沿江城市呈现人口上升趋势,而内地传统城市则呈现人口下降的趋势。这主要反映了

A.帝国主义对中国侵略的加剧 

B.人们对城市生活的向往

C.中国经济的外向型特征逐步体现 

D.自然经济日趋解体

查看答案
微信公众账号搜索答案