1.简答题- (共1题)

已知,步骤Ⅰ中固体全部消失,溶液呈蓝色,无气泡产生。请回答下列问题:
(1)原固体中一定含有的物质是___________;
(2)原固体中一定不含有的物质是___________,证据是___________;
(3)任写一个步骤Ⅲ中发生反应的化学方程式___________
(4)步骤Ⅲ所得浅绿色滤液中一定含有的溶质是___________。
2.科学探究题- (共1题)

(1)分别向两支装有碳酸钠和碳酸钙粉末的试管中注入一定量的稀盐酸,两支试管内均观察到的现象是___________,固体粉末全部消失,最终形成无色溶液。
(2)实验结束后,同学们将A、B两支试管中的废液倒入同一只洁净的烧杯中,发现烧杯中的废液变浑浊。过滤,对滤液中的溶质成分进行探究,请你一起参与。
(提出猜想)
猜想1:滤液中的溶质是氯化钠;
猜想2:滤液中的溶质是氯化钠和碳酸钠;
猜想3:滤液中的溶质是___________。
实验步骤 | 预计实验现象 | 预计结论 |
取少量的滤液于试管中,______ | ______ | 猜想______正确 |
(设计实验)请你选择一种猜想进行验证。
3.计算题- (共1题)

(1)请分析当BaCl2溶液滴加到B点时,溶液中的溶质是 。
(2)请计算当滴加BaCl2溶液至图中A点时,所得溶液的溶质质量分数(计算结果保留一位小数)。
4.单选题- (共10题)
A.现象与解释:热胀冷缩——分子大小改变 |
B.家庭卫生与相关原理:水中加入洗洁精去油污——溶解油污 |
C.实验操作与安全:稀释浓硫酸——把水倒入浓硫酸里 |
D.环境问题与相关物质:温室效应——CO2 |
选项 | 物质 | 杂质 | 除去杂质的方法 |
A | NaCl | 泥沙 | 加入水溶解,过滤,蒸发 |
B | N2 | O2 | 通过红热的铜丝 |
C | KNO3溶液 | Ba(NO3)2 | 滴加适量K2SO4溶液、过滤 |
D | NaOH溶液 | Na2CO3 | 滴入足量稀盐酸至不再产生气体 |
A.A | B.B | C.C | D.D |
A.用湿毛巾捂住口鼻 |
B.趴在地上匍匐前进向外逃生,莫站立 |
C.当逃生通道被切断时,关紧门窗,用水浸湿棉被蒙上门窗,防止烟火渗入,固守待援 |
D.高楼发生火灾,应该跳楼逃生 |
5.选择题- (共2题)
2C(石墨,s)+H2(g)═C2H2(g);△H=b
2C(石墨,s)+2H2(g)═C2H4(g);△H=c
已知:a>c>b,对下列反应:C2H2(g)+H2(g)═C2H4(g);△H=x
2CH4(g)═C2H4(g)+2H2(g);△H=y
判断正确的是( )
根据首字母提示,完成短文填空。
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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.”
6.填空题- (共8题)
(2)制作“叶脉书签”需要100g溶质质量分数为10%的氢氧化钠溶液.请问:若用20%的氢氧化钠溶液和水配制,需要20%的氢氧化钠溶液质量是 g。

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【1】题量占比
简答题:(1道)
科学探究题:(1道)
计算题:(1道)
单选题:(10道)
选择题:(2道)
填空题:(8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:8
7星难题:0
8星难题:8
9星难题:4