一、考点、热点回顾
1、固体物质的颜色
A 白色固体:氧化钙 CaO 、氢氧化钙Ca(OH)2 、碳酸钠Na2CO3、碳酸钙CaCO3、氢
氧化钠NaOH、
B 黄色固体:硫粉S
C 红色固体:红磷P、氧化铁Fe2O3、铜Cu
.
D 蓝色固体:胆矾CuSO45H2O
E 黑色固体:木炭C、氧化铜CuO、二氧化锰MnO2、四氧化三铁Fe3O4、 F 绿色固体:碱式碳酸铜Cu2(OH)2CO3 G 紫黑色固体:高锰酸钾KMnO4 H 无色固体:冰,干冰,金刚石
I 银白色固体:银,铁,镁,铝,汞等金属
2、生成沉淀的颜色
A 白色沉淀:不溶于水也不溶于稀硝酸:氯化银AgCl、硫酸钡BaSO4
不溶于水但溶于稀硝酸或稀盐酸:氢氧化镁Mg(OH)2、
碳酸钙CaCO3、碳酸钡BaCO3
B 红褐色沉淀:氢氧化铁Fe(OH)3 C 蓝色沉淀:氢氧化铜 Cu(OH)2
3、 溶液的颜色
A 蓝色溶液Cu2+:硫酸铜CuSO4、硝酸铜Cu(NO3)2 、氯化铜CuCl2等
B 黄色溶液Fe:氯化铁FeCl3、硫酸铁Fe2(SO4)3、硝酸铁Fe(NO3)3等
2+
C 浅绿色溶液Fe:氯化亚铁FeCl2、硫酸亚铁FeSO4、硝酸亚铁Fe(NO3)2等
D无色液体:水,双氧水
E 紫红色溶液:高锰酸钾溶液 F 紫色溶液:石蕊溶液
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4、气体的颜色
A 红棕色气体:二氧化氮 B 黄绿色气体:氯气
C 无色气体:氧气,氮气,氢气,二氧化碳,一氧化碳,二氧化硫,氯化氢气体等大多数气体。
二、典型例题
1.A、B、C、D、E、F、G为常见的物质,其中B、E、G属于单质,反应②是炼铁工业中
的主要反应,下图是它们之间的相互转化关系。请回答:
C A 过量稀盐酸 ① X溶液 ③ O2 加热 ④ E 红色固体
F 浅绿色溶液
G 无色气体 B Y 高温 ② D(1)A物质的化学式 。
(2)写出反应②的化学方程式 ,
C物质固态时的名称 ,该固体物质在实际生活中的一种用途是 。 (3)写出反应③中生成红色固体的化学方程式 。
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(4)上图转化中产生无色气体G的原因是 ,
写出物质G和A在加热条件下反应的化学方程式
2.现有初中化学中常见的易溶于水的三种钠盐组成的混合物,将其溶于水后得无色溶液A,进行如下实验并得到相应结果:
试回答下列问题:
(1)无色气体D的化学式为 ,白色沉淀E的化学式为 ,钡盐B的化学式为 。
(2)原混合物中含有的三种易溶于水的钠盐的化学式分别为 、 、 。 3.为了除去食盐(主要成分为NaCl)样品中含有少量的氯化镁和硫酸钠杂质,某学生根据氯碱工业中精制食盐水的基本原理,运用所学知识设计了如下图所示的①至⑤步除杂方案:
甲 沉 淀 乙 ② ① 沉 过量 A 淀 水 NaOH溶液 样丙 溶 ③ 过滤 溶解 品 沉 液 过量 淀 ④ B BaCl2溶液 滤 过量 过滤 液 C Na2CO3溶液 ⑤ 滤 过滤 过量 液 固D 盐酸 体滤 加热蒸发 丁 液 请根据上述除杂方案,回答下列问题: (1)沉淀甲是 ;滤液C中的溶质是 ; 操作⑤中加入过量盐酸的作用是 。
(2)假设整个操作过程中物质转化无损失,则固体丁中NaCl的质量比原样品中NaCl的质量 (填增大、不变或减小);若在操作②中改为加过量的KOH溶液,固体丁中可能含有的杂质是 。
4.有A、B、C、D、E、F六种物质的稀溶液,已知它们分别是K2CO3、BaCl2、Ca(NO3)2、NaCl、H2SO4、AgNO3中的某一种溶液。下图为常温时上述溶液两两混合的部分实验现象,其中“↓”表示生成沉淀,“↑”表示生成气体,“—”表示无明显现象或生成微溶物。
小资料 部分盐的溶解性表(20℃) NO3? 溶 溶 溶 2?2?Cl? SO4 CO3 Ba2? Ca2? Ag? 溶 溶 不溶 不溶 微溶 微溶 不溶 不溶 不溶
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请回答下列问题:
(1)在下图中的空格内用“↓”“↑”“—”表示出对应反应的实验现象。
(2)F是__________。
5.现有A、B、C、D、E、F、G七种物质,C、F是最常见的金属,B是气体单质,D为浅绿色溶液,G为蓝色溶液,它们之间存在如下关系:
(1)试推测下列物质的化学式:B_________,D_________,F_________。 (2)写出C→A转化的化学方程式:__________________。
6.A、B、C、D、E是初中化学中常见的5种无色气体,其中2种是单质,3种是化合物。它们之间的转化关系如下图所示。
请写出你的推断结果:
A ,B ,C ,D ,E 。
7.A.、B、C、D、E、F、G、H、I都是初中化学学过的物质。其中E、F、H均为黑色固体。B为紫红色固体,D为混合物。他们之间有下图的转化关系(部分生成物已省去)
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(1)用化学式表示D的组成 、 (2)F→G的反应类型
(3)写出F→E的化学方程式 (4)指出B的一种用途
1. What do you think ____ solve the problem?
A. you can do B. can you do C. you can do to D. can you do to 2. In the past he often made his sister ____, but now he is often made ____ by his sister.
A. to cry; to cry B. cry; cry C. to cry; cry D. cry; to cry 3. The teacher told us that the sun ____ in the east. A. rises B. rose C. raises D. raised 4. He lives in a village ____ there are a lot of trees. A. there B. where C. that D. which 5. He ____ Alice for ten years.
A. married to B. has married to C. has married D. has been married to
6. We need fifteen more people ____ our team to do the job. A. but B. except C. as well D. besides 7. They won't allow us ____ at this beach.
A. swimming B. to swim C. swam D. swim 8. Is this factory ____ you visited last week?
A. that B. where C. the one D. in which
9. The reason ____ he was absent from the meeting was ____ his car broke down on the way.
A. that; because B. why; that C. that; that D. for; that 10. Is the river ____ through that town very large?
A. which flows B. flows C. that flowing D. whose flows
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11. The teacher told me that the students I wanted to see were seen ____ football on the playground just now.
A. playing B. to be playing C. play D. to play 12. The red rose is the only one ____ I real like. A. which B. who C. that D. whom
13. All the apples ____ fell down were eaten by the pigs. A. those B. which C. what D. that
14. Don`t forget the day ____ you were received into the Youth League.
A. when B. that C. at which D. where 15. I prefer ____ at home to ____ outside.
A. staying, playing B. to stay, play C. staying, play D. to stay, playing
16. The box is ____ what I saw in the shop.
A. same as B. the same like C. the same that D. the same as 17. The pen ____ she writes letters is broken. A. which B. that C. with which D. by which 18. Would you like to ____ us in our discussion.
A. take part in B. join C. taking part in D. joining 19. I'm sure the red team will ____ the game. A. win B. beat C. defeat D. succeed
20. Ahead of me I saw a woman ____ I thought was my aunt. A. who B. whom C. of whom D. whose
21. ____ your help, everything in the room is in good order now. A. Since B. Because C. thanks for D. Thanks to 22. He is known to the world and has a lot of friends ____. A. in and out of abroad B. at home and abroad
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