问题 实验题

下图所示为实验室常用的实验装置:

(1)写出下列仪器名称:a      ;b      

(2)实验室用高锰酸钾制取氧气时,应选择的发生装置是        (填字母代号),化学方程式是                           ,用双氧水制取氧气的化学方程式为                         

(3)实验室用锌和稀硫酸反应制取氢气的化学方程式是                     ,若将E装置中收集的氢气排出,应从       (填c或d)口通入蒸馏水。

(4)装置C相对于装置B在操作方面的优势为        

A.可以随时加液      B.可以控制反应速率    C.可以控制反应发生与停止

(5)如图是某同学放置在桌面上的一瓶初中常见的无色纯净气 体,该气体可能是_____ (填化学式,只填一种),你如何用实验方法确定该瓶中盛放的气体___________________

(6)甲烷是密度小于空气,极难溶于水的气体。实验室用加热无水醋酸钠和碱石灰固体混合物的方法来制取。制取甲烷应选用的发生装置是     ,得到较纯净的甲烷应选用的收集装置是          

答案

(1)酒精灯,长颈漏斗 (2) A ;2KMnO4K2MnO4+MnO2+O2↑;2H2O22H2O+ O2↑。(3)Zn + 2HCl= ZnCl2 + H2↑;C (4)C (5)O2;将带火星的木条伸入集气瓶中,木条复燃,证明是氧气。(CO2,将澄清石灰水倒入瓶中,震荡,有浑浊出现,证明是二氧化碳)(6)A、   D

题目分析:由题中所给图示可知(1)仪器a为酒精灯,b为长颈漏斗;(2)实验室用高锰酸钾制取氧气,因为高锰酸钾状态为固态,反应条件为加热,所以选择固液加热型装置A,其反应的化学方程式为:2KMnO4K2MnO4+MnO2+O2↑,用双氧水制取氧气的化学方程式为:2H2O22H2O+ O2↑;(3)实验室用锌和稀硫酸反应制取氢气的化学方程式是Zn + 2HCl= ZnCl2 + H2↑;因为水进入要从下向上充满集气瓶,氢气还要排除形成一个循环,所以若将E装置中收集的氢气排出,应从C口通入蒸馏水。因为装置C中固体和液体分离,相对于装置B的优点为C可以控制反应发生与停止;(5)右图是某同学放置在桌面上的一瓶初中常见的无色纯净气体,因为该气体的放置放法可知密度比空气大,所以该气体可能是O2或CO2;验证方法为将带火星的木条伸入集气瓶中,木条复燃,证明是氧气或将澄清石灰水倒入瓶中,震荡,有浑浊出现,证明是二氧化碳;(6)由反应物的状态及反应条件可确定采用固体加热型装置A;生成的甲烷密度比空气小,极难溶于水,选择的收集方法为排水集气法D或向下排空气法.

单项选择题

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

With the implementation of (1) , the so - called network has become a reality. The provision of such facilities is the most important part of the network requirements. However, in many applications the communicating computers may be of different types. This means that they may use different programming languages and, more importantly, different forms of (2) interface between user(application) program, normally referred to, as application processes, and the underlying communication services may be (3) . For example, one computer may be a small single - user computer, while another may be a large (4) system. In the earlier days of computer communication, these issues meant that only closed communities of computers (that is, from the same manufacturer) could communicate with each other in a meaningful way. IBM’s Systems Network Architecture (SNA) and DEC’s Digital Network Architecture (DNA) are just two examples of communication software packages produced by manufacturers to allow their systems to be interconnected together. These proprietary packages, however, of which there am still many inexistence, do not address the problem of universal interconnect ability, or open systems interconnection. In an attempt to alleviate this problem, (5) , in the late 1970s, formulated a reference model to provide a common basis (or the coordination of standards developments and to allow existing and evolving standards activities to be placed into perspective with one another.

5()

A.DNA

B.SNA

C.the OSI

D.the ISO

单项选择题