1.综合题- (共1题)


得到如下数据:
装置 | B | C |
反应前质量 | 86.3g | 284.2g |
反应后质量 | 83.9g | 286.9g |
(1)请计算样品中氧化铁的质量分数.(写出计算步骤,计算结果精确到0.l%)_______
(2)该实验还可测定组成水的各元素之间的质量关系,请用表中实验数据列式表示出水中氢、氧元素的质量比为_____________________________________________________________________(不用化简);若玻璃管中的氧化铁没有完全反应,则求得水中氢、氧元素的质量比会________(选填“偏大”、“偏小”或“不变”).
2.科学探究题- (共1题)

[提出问题]无色气体A有哪些成分?红色固体B可能是什么?
[猜想与假设]甲认为无色气体A一定是CO2,因为CO与CuO反应的化学方程式为 .乙认为红色固体B一定是Cu.
[交流与讨论]丙认为甲的猜想不一定正确,无色气体A除含CO2外,可能含CO,理由是 .
[探究与反思]
(1)为验证甲的猜想,大家按以下图示进行实验,过程和现象如下(箭头表示气体流向):

由此,你认为甲的猜想 (选填“正确”或“不正确”).
(2)为验证乙的猜想,大家按以下图示进行实验探究,过程和现象如下:

经过分析,大家确认乙的猜想是错误的,理由是(要求写出分析过程): .
(3)为探究红色粉末M的组成,丁同学做了如下实验:
取洗净、烘干的7.2g红色粉末M,放在纯氧气流中加热,观察到粉末由红色逐渐变为黑色.充分反应,冷却、称量,质量为8.0g.将该黑色粉末放于足量稀硫酸中,黑色粉末全部溶解,得到蓝色溶液.大家分析、讨论、计算,最后得出红色粉末M的组成元素是 ,红色粉末M的化学式为 .
3.单选题- (共7题)

A.反应前后分子种类没有改变 | B.该反应属于置换反应 |
C.该反应不符合质量守恒定律 | D.图示中共有4种分子 |
A.NaCl,+1 | B.H2,+3 | C.HCl,+1 | D.NaCl,﹣1 |
A.除去铜粉中混有的铁粉 |
B.除去熟石灰中的石灰石 |
C.区别硝酸银和硝酸钠溶液 |
D.检验暴露在空气中的NaOH固体是否变质 |
A.用食醋除去松花蛋的涩味 |
B.食品袋里充入氮气延长食品的保质期 |
C.在果汁中加入“塑化剂”使其口感更好 |
D.在煲好的鸡汤中放入适当的加碘食盐 |
A.6.4g | B.3.2g | C.1.8g | D.1.6g |
4.选择题- (共9题)
根据短文理解,选择正确答案。
Rafting the GRAND CANYON Welcomes You!
For an exciting,fun and challenging white water tours,Rafting the GRAND CANYON is here to help you plan the right tour for you. Whether you want to travel for two days or ten,hike in or not,go on an oar raft or motorized trip,we will help you find the trip that meets your needs.
For those who will be vacationing on the offseason a trip on the Native American Red River rafting is available year around or a one day trip is available on the Colorado River from Diamond Creek to Pierce Ferry (about three hours from Las Vegas).
Most of the trips depart from Lees Ferry,Arizona (approximately 21/2 hours from the south rim of the Grand Canyon).We offer partial trips which allow you to get on or off at Phantom Ranch located at the bottom of the Grand Canyon National Park South Rim. Requiring a hike in or out,with proper planning the horse ride up or down is also an option. Most trips occur between April and October.
Since all rafting on the Colorado requires a permit,planning and reserving your trip requires reservations well in advance. Please let us know when you would like to go and we will contact all the river concessionaires (特许权获得者)to help you find the best trip for you.
For planning your trip,questions,concerns or to make your reservations,please email or call the toll free number below. Since these trips are limited we highly recommend you make your reservations months in advance.
To talk to a live person call us toll free:18002226966 or 7026556060
If you have any questions regarding a trip,please CLICK_HERE to fill out our form. This will speed up the process of getting you accurate information regarding your trip.
If you would like to send us an email other than about an upcoming trip you can contact us at info@raftingthegrandcanyon.com.
We look forward to helping you plan your trip! (Please NO Travel Agents)
根据短文理解,选择正确答案。
Rafting the GRAND CANYON Welcomes You!
For an exciting,fun and challenging white water tours,Rafting the GRAND CANYON is here to help you plan the right tour for you. Whether you want to travel for two days or ten,hike in or not,go on an oar raft or motorized trip,we will help you find the trip that meets your needs.
For those who will be vacationing on the offseason a trip on the Native American Red River rafting is available year around or a one day trip is available on the Colorado River from Diamond Creek to Pierce Ferry (about three hours from Las Vegas).
Most of the trips depart from Lees Ferry,Arizona (approximately 21/2 hours from the south rim of the Grand Canyon).We offer partial trips which allow you to get on or off at Phantom Ranch located at the bottom of the Grand Canyon National Park South Rim. Requiring a hike in or out,with proper planning the horse ride up or down is also an option. Most trips occur between April and October.
Since all rafting on the Colorado requires a permit,planning and reserving your trip requires reservations well in advance. Please let us know when you would like to go and we will contact all the river concessionaires (特许权获得者)to help you find the best trip for you.
For planning your trip,questions,concerns or to make your reservations,please email or call the toll free number below. Since these trips are limited we highly recommend you make your reservations months in advance.
To talk to a live person call us toll free:18002226966 or 7026556060
If you have any questions regarding a trip,please CLICK_HERE to fill out our form. This will speed up the process of getting you accurate information regarding your trip.
If you would like to send us an email other than about an upcoming trip you can contact us at info@raftingthegrandcanyon.com.
We look forward to helping you plan your trip! (Please NO Travel Agents)
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I don't encourage people to take photographs like this without {#blank#}1{#/blank#}(允许), but by law we can publish.
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5.填空题- (共3题)
(1)二甲醚属于 (填“酸”、“碱”、“盐”、“氧化物”或“有机物”中一种)。
(2)二甲醚的一个分子中,C、H、O三种原子的个数之比为 (填最简整数比)。
(3)二甲醚中,C、O两元素的质量之比为 (填最简整数比)。
(4)二甲醚可由合成气(CO和H2)在一定条件下制得.用合成气制二甲醚时,还产生了一种可参与大气循环的常温下为液体的氧化物,该反应的化学方程式是: 。
(1)注意饮水安全,保证人体健康,在天然水净化过程中,人们常用活性炭去除异味和色素,这是利用活性炭的 性.
(2)若要测定大明湖水质的酸碱性强弱,最适宜的是(填序号) .
A.酚酞试液 B.pH试纸 C.石蕊试液
(3)水是最常用的溶剂.如图是甲、乙两种固体物质的溶解度曲线.

① ℃时,甲、乙两种物质的溶解度相等.
②t2℃时,将等质量的甲、乙两种物质加水溶解配制成饱和溶液,所得溶液质量的大小关系为:甲 乙(填“>”、“<”或“=”之一).
③把甲物质的不饱和溶液变为饱和溶液,下列有关说法正确的是 (填序号)
A.溶剂的质量一定变小 B.溶质的质量可能不变
C.溶质的质量分数一定变大
A.溶液的质量一定变大. |
(1)一种非金属单质:
(2)一种非金属氧化物:
(3)一种难溶的碱:
(4)一种可溶的盐: 。
6.实验题- (共1题)
-
【1】题量占比
综合题:(1道)
科学探究题:(1道)
单选题:(7道)
选择题:(9道)
填空题:(3道)
实验题:(1道)
-
【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:3
5星难题:0
6星难题:6
7星难题:0
8星难题:4
9星难题:0