问题 问答题

食盐是用途极为广泛的化学物质.在厨房里,它是最重要的调味品;在医药上,它用于配制生理盐水;在化工厂,它是生产盐酸、烧碱的基本原料,通过电解饱和氯化钠的水溶液,可以制得烧碱.为了检验某烧碱产品中是否含有氯化钠,进行下面的操作:

(1)取样,用蒸馏水充分溶解配成溶液;

(2)往溶液中逐滴滴入适量的硝酸;

(3)再往溶液中滴入几滴硝酸银溶液.如果______则说明样品中含有氯化钠,化学方程式为______.此反应的基本类型是______.操作(2)的目的是______.

答案

(3)氯化钠能与硝酸银反应生成氯化银白色沉淀和硝酸钠,此反应是复分解反应,在溶液中加入适量的硝酸能中和氢氧化钠.

故填:产生白色沉淀,NaCl+AgNO3=AgCl↓+NaNO3,复分解,中和NaOH.

阅读理解

第二节:任务型阅读(共5小题;每小题1分,满分5分)。阅读下面六个选项(A、B、C、D、E和F),选出符合各自需求的最佳选项。选项中有一个是多余选项。

_______ 75. Carter’s daughter is about five years old. She has her own room. Carter wants to paint her room pink because the little girl likes pink. Meanwhile their house needs new wallpaper. Carter wants some professionals to help with the job.

________76. The Millers move into a small house which has a history of 30 years. They are pleased with the environment but not the electrical work. They have a lot of household appliances (家用电器) which require good electrical support. They need help.

________77. Mrs. Hill finds there is something wrong with her shower room. Each time she takes a shower, a lot of water spreads out of the shower room into the living room. She has to find someone to fix the shower room.

________78. Andrew, a carpenter, has a customer who wants to make some furniture for his new house. Andrew can help him, but he needs some wood first.

________79. Edward is considering paving the driveway. He wants know how he can get some stones.

A. We are one of the most famous stone factories. We have specialized in stone for many years, and we have many kinds of stones used widely in building, landscape, etc. all in high quality, filling at the price!

B. Experienced builder and decorator---interior and exterior painting, plastering, wallpapering, flooring, carpet fitting, tiling. Call for free quotation (报价单) and unbeatable prices, 13236467211/07834224451.

C. Building & window designs for electrical work---All electrical work undertaken include rewiring, power upgrades, fault finding, emergencies, extra sockets(插座), door entry systems, interior and exterior lighting. Twenty four hours call out. 48303560

D. EX kitchen offers complete and professional service, all leading brands are available; all associated building works are undertaken. 07092424744.

E. Building / Repair. From shelves to shower rooms, from fitting kitchens / bathrooms to painting and paperhanging. 20-year experience. Friendly, prompt and reliable, qualified. 019035334477.

F. Wood! Wood! Wood! At Bristol Wood Recycling Project. Wide selection, always changing, bargain prices. Hard, soft, flooring & dimensioned wood. Cutting, sanding (砂纸打磨) & delivery service. Tel: 01179723219. Open Mon-Fri.

单项选择题