1.选择题- (共14题)
①小黄取废液于试管中,滴加紫色石蕊试剂,观察到废液呈白色浑浊状态,溶液仍然为紫色.她认为废液中上层清液一定含有NaCl,我认为还应该有{#blank#}1{#/blank#},可能有{#blank#}2{#/blank#}.
②小亮取废液加入酚酞试液,发现酚酞没变红色,他认为废液是安全的,可以直接排放.我认为他的结论不正确,溶液还可能显酸性.我取少量废液,再加入{#blank#}3{#/blank#},出现{#blank#}4{#/blank#}的现象,说明我的猜测是正确的.
③小明取废液缸里的废液于试管中,观察到废液也呈白色浑浊状态,用pH试纸测得废液的pH=9.废液中的碱性物质是什么?经过思考,小明认为可能是(a) NaOH和Na2CO3;(b) NaOH;(c) Na2CO3.为了验证猜想,小明设计如下实验:
实验步骤 | 现象 | 结论 |
取上层清液,{#blank#}5{#/blank#} | {#blank#}6{#/blank#} | a结论正确 |
于是,小明向试管中加入稀盐酸,边加边测试,直到pH=7,同时观察到沉淀逐渐溶解.小明觉得废液经过如上处理后可以放心倒掉.其相关的化学方程式是(任写一个){#blank#}7{#/blank#}.
④经过讨论,小亮认为,小明的方案不完善,因为小明对废液中含有的Ba2+没有处理,而Ba2+是重金属离子,会造成更严重的污染.
小亮采用了另外一种方案:他另取废液缸里的废液于试管中,向试管中加入{#blank#}8{#/blank#},直至废液pH=7,且沉淀不再增加.他觉得废液这样处理后才可以倒掉.请写出在此与沉淀有关的化学方程式{#blank#}9{#/blank#}.
⑤老师肯定了小亮的方案,因为他考虑得更全面.小亮方案的优点在于{#blank#}10{#/blank#}.
为了防止考生作弊,中考监考人员往往会利用手持式金属探测器对考生进行检查,如图所示,当靠近金属物体时,在金属导体中就会产生感应电流,探测器发出警报.下图中能反映出金属探测器工作原理的是
第一步:验证废水酸性.往废水中滴加石蕊试液,石蕊变{#blank#}1{#/blank#},说明废水呈酸性.
第二步:处理废水.该小组同学设计了以下两个方案.
方案一:用熟石灰处理废水,其反应的化学方程式为{#blank#}2{#/blank#}.
方案二:用BaCl2处理废水,观察到废水中出现{#blank#}3{#/blank#}.
经过分析,同学们认为方案二没有达到处理废水的目的,因为处理后的废水中含有较多的{#blank#}4{#/blank#}.
2.单项选择- (共24题)
A.A; a | B.The; the | C.The; a | D.A; the |
A./; / | B.a; the | C.the; an | D.a; an |
A.sentence; / | B.be sentenced; / | C.be sentenced; the | D.sentence ; the |
A.prove | B.proving | C.being proved | D.proved |
A.take apart | B.turn down | C.break down | D.pack up |
A.prevent | B.survive | C.keep | D.quit |
A.remains | B.is remained | C.is remaining | D.has been remained |
A.raise; raises | B.rise; rises | C.raise; rises | D.rise; raises |
A.to be the best | B.as the best one | C.the best | D.being the best |
A.turn off | B.turn to | C.turn out | D.turn away |
A.compete | B.equal | C.win | D.suit |
A.injured | B.devoted | C.buried | D.trapped |
A.be | B.has been | C.should have been | D.was |
A.settle down | B.break down | C.set up | D.set down |
--They are _____ a thief.
A.searching; searching | B.searching for; searching |
C.searching; searching for | D.searching for; searching for |
A.discussing | B.discussed | C.to be discussed | D.being discussed |
--He _______, because he could’t do that himself.
A.had it repaired | B.had it to repair |
C.had it repairing | D.had repaired it |
A.shocking; shocking | B.shocking ; shocked |
C.shocked; shocked | D.shocked ; shocking |
A.in that; that | B.in which; that | C.that; which | D.in which; which |
A.lost your job | B.been out of work | C.been lost your job | D.out of work |
A.its | B.whose | C.where | D.which |
A.realized they | B.did they realized |
C.did they realize | D.they did realize |
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【1】题量占比
选择题:(14道)
单项选择:(24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:24
7星难题:0
8星难题:0
9星难题:0