1.科学探究题- (共1题)

(提出猜想)王老师提示,这瓶无色溶液只能是下列四种溶液中的一种:
①硫酸镁溶液,②硫酸钠溶液,③硫酸溶液,④硫酸铵溶液。
(查阅资料)(1)常温下,常见物质的溶解度如下:
物质 | MgSO4 | Na2SO4 | (NH4)2SO4 | H2SO4 |
溶解度 | 35.1g | 19.5g | 75.4g | 与水以任意比互溶 |
(2)(NH4)2SO4的水溶液显酸性
(实验探究)(1)通过查阅资料,小明同学认为猜想__________ 不成立(填序号),原因是________
(2)为确定其他几种猜想是否正确,小明同学继续进行探究:
实验操作 | 实验现象 | 实验结论 |
①取该溶液少许于试管中,向其中滴加几滴________(合理答案均可)溶液 | 溶液中有白色沉淀生成 | 猜想①成立 |
②用玻璃棒蘸取少许原溶液滴在pH试纸上,并跟标准比色卡对照 | 溶液pH小于7 | 猜想③成立 |
小雅同学认为,小明实验操作②的结论不正确,她的理由是________
(3)请你设计实验方案,确认该溶液是硫酸铵溶液,并完成实验报告。
实验操作 | 实验现象 | 实验结论 |
取该溶液少许于试管中, ________ | ________ | 猜想④成立,该反应的化学方程式为 ________ |
2.单选题- (共3题)

(说明:一种小球代表一种原子)则下列说法正确的是
A.图示中的反应物都是单质 | B.该反应属于置换反应 |
C.图示中共有4种分子 | D.该反应不符合质量守恒定律 |
3.选择题- (共1题)
根据首字母提示,完成短文填空。
Cannon has shown a great interest in collecting flags. At the young age of four, Cannon began studying flags, d{#blank#}1{#/blank#} them in his coloring books and putting them up on his walls. Throughout school, he studied flags and tried to find out all he could about them. After university, Cannon s{#blank#}2{#/blank#} to be a lawyer. Throughout law school, he continued to collect flags. His classmates, friends, and family started c{#blank#}3{#/blank#} him “the flagman.”
Cannon now has more than 200 flags in his collection. He shows many of them in his downtown law office. Once he d{#blank#}4{#/blank#} country flags for an exhibition on the Olympics.
In addition to collecting flags, Cannon also w{#blank#}5{#/blank#} about them. He has published three books about flags. He loves to h{#blank#}6{#/blank#} from friends who see his b{#blank#}7{#/blank#} in stores all over the world. A few years ago, Cannon's hobby r{#blank#}8{#/blank#} a new level. He entered a flag design contest and won. The country he lives in asked him to design its f{#blank#}9{#/blank#}. Cannon explains his hobby this way, “Collecting flags is l{#blank#}10{#/blank#} collecting pieces of history.”
4.填空题- (共1题)

(1)图一:该变化对应的实验操作是将______滴加到另一种溶液中。当滴入溶液的质量为ag时,溶液中的溶质为________(填化学式)。当溶液的pH=7时,溶液中的溶质___________。当加入溶液的质量为40g时,向所得溶液中滴加紫色石蕊试液,溶液呈_________ 色。
(2)图二:表示酸碱恰好完全反应的点是____,说明该反应伴随_____现象(填“放热”或“吸热”)。
(3)如果实验中用去了20g溶质质量分数为4%的氢氧化钠溶液,根据图示计算稀盐酸中溶质的质量分数____。
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【1】题量占比
科学探究题:(1道)
单选题:(3道)
选择题:(1道)
填空题:(1道)
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【2】:难度分析
1星难题:0
2星难题:0
3星难题:0
4星难题:0
5星难题:0
6星难题:3
7星难题:0
8星难题:2
9星难题:0