问题 问答题

现有盐酸、氢氧化钠、氢氧化钙三瓶失落标签的溶液,小亮为了鉴别这些溶液,将它们编号为A、B、C,并按下图步骤进行实验,观察到以下现象:

(1)写出所加溶液a的名称:______,写出C溶液中溶质的化学式:______

(2)小芳认为只要加入溶液a和溶液b中的一种试剂,就能直接鉴别出三种物质,小芳的观点正确吗?请说明理由.______

(3)写出上述反应中生成白色沉淀的化学方程式______.

答案

(1)加入溶液a,A、B、C三种溶液没有变成新的物质,所以断定溶液a是指示剂.指示剂能使AC两种溶液变红,

说明指示剂是酚酞(酚酞遇到碱溶液变红),B是盐酸,AC是氢氧化钙或者氢氧化钠.因为碳酸钙是白色沉淀,所以A是氢氧化钙,C是氢氧化钠.故答案为:酚酞溶液,NaOH.

(2)碳酸钠和盐酸反应有气体生成,碳酸钠和氢氧化钙反应生成碳酸钙(白色沉淀),碳酸钠和氢氧化钠不会反应.故答案为:正确,可在三个溶液中分别加入碳酸钠溶液,有气体生成的是盐酸,有沉淀生成的是氢氧化钙,没有现象的是氢氧化钠溶液.

(3)碳酸钠和氢氧化钙反应生成碳酸钙和氢氧化钠,书写化学方程式要注意配平和沉淀符号.故答案为:

Ca(OH)2+Na2CO3=2NaOH+CaCO3↓.

阅读理解

A villa (别墅) designed to resist earthquakes with “self-healing” cracks in its walls, thanks to nanotechnology (纳米技术) applications with self-healing polymers (聚合物), is to be built on a Greek mountainside. The villa’s walls will include special particles that turn into a liquid when squeezed (压榨) under pressure, flow into cracks, and then harden to form a solid material.

The NanoManufacturing Institute (NMI), based in Leeds University, will play a key role in an EU project to construct the home by December 2010. The project, called “Intelligent Safe and Secure Buildings” (ISSB) is funded under the EU’s Sixth Framework program. This potentially life-saving scheme is led by German building manufacturer Knauf. The villa will be built in Amphilochia, in western Greece, where Knauf currently runs a manufacturing plant. If the experiment is successful, more tremor-resistant(防震)homes could be built in earthquake zones across the globe. NMI chief executive Professor Terry Wilkins said, “What we’re trying to achieve here is very exciting. We’re looking to use polymers in much tougher situations than ever before on a larger scale.” Monitors contained in the villa’s walls will be able to collect vast amounts of data about the building over time. Wireless sensors(传感器) will record any stresses and vibrations, as well as temperature, humidity and gas levels.

The walls are to be built from new load-bearing steel frames and high-strength gypsum(石膏)board. Prof Wilkins said, “If there are any problems, the intelligent sensor network will be able to alert residents immediately so they have time to escape. If whole groups of houses are so constructed, we could use a larger network of sensors to get even more information. If the house falls down, we have got hand-held devices that can be used over the ruins to pick out where the embedded(嵌入的)sensors are hidden to get some information about how the villa collapsed. Also, we can get information about anyone who may be around, so it potentially becomes a tool for rescue.”

小题1:The aim of the passage is to ________.

A.report a piece of interesting news

B.promote tremor-resistant homes

C.inform us of the nanotechnology development

D.tell us something about a tremor-resistant home小题2:The villa can resist earthquakes because _______.

A.it will be built on a special place

B.the cracks in its walls can be healed by the polymers

C.the special particles can make its walls stronger

D.the intelligent sensor network can tell people where there is a crack小题3:If the tremor-resistant home falls down, _______.

A.rescue work can be done more quickly and accurately

B.the intelligent sensor network will stop working

C.no one can be hurt in the earthquake

D.a warning signal will be given to other residents小题4:What Prof Wilkins said suggests that _______.

A.he is doubtful about the project

B.he thinks the tremor-resistant home is perfectly designed

C.he is confident in the tremor-resistant home

D.the tremor-resistant home still needs to be tested in a real situation小题5:It can be inferred from the passage that tremor-resistant home _______.

A.is still being tried out

B.is already under construction

C.has been in wide use

D.will be put into wide use soon

单项选择题