北京市2021届中考化学试卷
※题型：单选题※知识点：单选题※试题难度：中等<br>空气中体积分数约占78%的气体是( )<br>A.二氧化碳 B.氮气 C.氧气 D.稀有气体<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2020/3539dcc19ed4439792004f0c3ff4e193/76900E09FAB5EBA344B8EA84E844FF07.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2020/d7daed8499354536aebd3de15fc994d3/40B7ADA442A28EFB40A43251223A3CA7.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>下列物质在<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>中燃烧,火星四射,生成黑色固体的是( )<br>A.木炭 B.镁条 C.蜡烛 D.铁丝<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/01da8127d1ac45a6be4e70f3a475d831/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/8f903cf1c7eb44b7b777c35d63550632/87AFFDE5BE3E8DE5031ADC913862389B.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>将<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>通入下列液体中,能产生白色沉淀的是( )<br>A.水 B.稀硫酸 C.食盐水 D.澄清石灰水<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/4af22b98fa52455380a14489ba70e5af/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/8b4b35a0473e4362a57440c99d29bcdc/EDC24B8AC3BF962A6AF6745F88054F46.png"><br><br>※题型：单选题※知识点：单选题※试题难度：容易<br>下列物质能用作氮肥的是( )<br>A.KCl<br>B.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/5B8D38F2053ED42E3CF96259C61F9F65.png"><br>C.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/C2920B52E90B7114DD19F38FB44C25B2.png"><br>D.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/2C99E65DA0F2DAE2B5001FEE0B20F410.png"><br><br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/1846b62e18ff47a2b2a4db13f0b99dcf/06CA09E70C17EF8BA2D3B8C70D693953.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/6e229fbb8ebd413babc8afcaebad0ece/6F50451742B392A1EDAB604ED9EB7D1D.png"><br><br>※题型：单选题※知识点：单选题※试题难度：容易<br>下列物质属于氧化物的是( )<br>A.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>B.CaO<br>C.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/022320F764A526311DCDA3EBFFF86FEA.png"><br>D.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/132CE5A4221DCE8F26C90950FF673643.png"><br><br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/f089af301c5649728c35ffe5ed292131/76900E09FAB5EBA344B8EA84E844FF07.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/3c32912493e242d4a489dddff33e9375/E9DEB7BD8385CC56FCB98440A9DAE76C.png"><br><br>※题型：单选题※知识点：单选题※试题难度：容易<br>下列仪器不能加热的是( )<br>A.烧杯 B.试管 C.量筒 D.燃烧匙<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/dc4e0f0931d24a089a3f6f07bb2e34f2/06CA09E70C17EF8BA2D3B8C70D693953.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/2436e18e79004081a4caaca0addde8b7/CE26FF1036D38D1AB386DA9A96176194.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>下列物质含有氢分子的是( )<br>A.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/640FA9CE9706385F659B022DD985CD4B.png"><br>B.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/FB0FEA1A772324307D17386FE5E24D6C.png"><br>C.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>D.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/BDF900345AF09A3015F45B2669FF3895.png"><br><br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/20ac4f77fa914e67a8e5c626b351b3ba/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/ca7958c687e7460983d31fa567addff7/ABB2206A60E47CB6FED4D693EA0D8CB1.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>下列物质能除铁锈的是( )<br>A.盐酸 B.植物油 C.NaOH溶液 D.食盐水<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/d02e57eec83c41818717227cbdb5f63f/E7F0EDF83F40244C8F0C84B97471AED6.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/5398cb88f86147e697632faca5b6b863/8B22D3D2B3C836B1DCA1021484E68B6C.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>下列元素中,人体摄入过低会引起贫血的是( )<br>A.铁 B.碘 C.锌 D.钙<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/4c604f7c035e4eb184055335118024a5/E7F0EDF83F40244C8F0C84B97471AED6.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/26831ec069354c1d8f6f8d605b4645a7/DF5626B53F9E1810CA639B06B797B3EE.png"><br><br>※题型：单选题※知识点：单选题※试题难度：容易<br>下列<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/BDF900345AF09A3015F45B2669FF3895.png"><br>的性质中,属于化学性质的是( )<br>A.难溶于水 B.无色气体 C.能燃烧 D.熔点低<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/45e1201ae2044e6f90c4e9dad58b3a06/06CA09E70C17EF8BA2D3B8C70D693953.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/0dc6434cb63c4b64ba04103882273f2c/4F4BE008ED02E4C501DFE9B017FDD757.png"><br><br>※题型：单选题※知识点：单选题※试题难度：较易<br>一些物质的pH范围如下,其中呈碱性的是( )<br>A.柠檬汁(2-3) B.酱油(4-5) C.西瓜汁(5-6) D.洗发水(8-9)<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/19032b70f3324b1caf918f18f71132da/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/f528f5bee7fe42c2ac221b9d7a8c4e1a/593EBF027FD57BE7ADA8CD70989A00E0.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>我国冶炼金属的历史悠久、回答<br>1-<br>问题。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/5F18FA1171AC69E40E2084821E44477A.png"><br>1.远古时期火法炼铜的原料是孔雀石(主要成分为<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/09E47BA6D4CE07817918FADC4A4F2046.png"><br>),组成<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/09E47BA6D4CE07817918FADC4A4F2046.png"><br>的元素种类为( )<br>A.3种B.4种<br>C.5种<br>D.6种<br>2.块炼铁以炭和铁矿石为原料,反应之一为<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/48C4F658E1986AC56545FCC42924F9DF.png"><br>,该反应中,化合价降低的元素是( )<br>A.铁元素<br>B.碳元素<br>C.氧元素<br>D.铁元素和碳元素<br>3.冶炼钛(Ti)的反应之一为<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/10B0B372C7DAC40033E062EB4E623A79.png"><br>,该反应属于( )<br>A.化合反应B.分解反应C.置换反应D.复分解反应A.化合反应<br>B.分解反应<br>C.置换反应<br>D.复分解反应<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/341cce167d9e43cbbbcd21cb55477562/BB01C8B382F734A60628A1F27B66B83E.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/ecd697c7bc3b45f49a23dc397c2d0041/74CBC97D474A007949D3225DBAA7E585.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>制作景泰蓝的釉料中常含钴元素。<br>钴<br>元素在元素周期表中的信息如下图。回答<br>1-2<br>问题。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/90407D0FDF124C50A21B569B805F8E2F.png"><br>1.下列有关钴元素的说法不正确的是( )<br>A.原子序数是27<br>B.属于非金属元素<br>C.元素符号是Co<br>D.相对原子质量为58.93<br>2.钴原子的核外电子数是( )<br>A.27<br>B.32<br>C.59<br>D.86<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/e651fe28204d41088468f5e55d0f179d/3254DFCB685D76D3B3222E8CFDFC06F5.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/8f7b89c07e8340698b4fa85a8dc8222a/248C3646007A31A3CBFD1B915F49AA8D.png"><br><br>※题型：填空题※知识点：填空题※试题难度：较易<br>用<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/1/23/0C7901C77903E8BAF76E821F809A46C4.png"><br>溶液喷洒路面可融雪、防尘。<br>20℃<br>时,按下表数据配制溶液,回答<br>21-23<br>问题。<br><tbody><br>序号<br>①<br>②<br>③<br>④<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/1/23/0C7901C77903E8BAF76E821F809A46C4.png"><br>的质量<br>/g<br><br>水的质量<br>/g<br>100<br>100<br>100<br>100<br></tbody><br>(已知:<br>20℃<br>时,<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/1/23/0C7901C77903E8BAF76E821F809A46C4.png"><br>的溶解度为<br>54.6g<br>)<br>1.所得溶液中,溶质与溶剂的质量比为1:2的是( )<br>A.①B.②<br>C.③<br>D.④<br>2.①中溶质的质量分数约为( )<br>A.23%<br>B.30%<br>C.35%<br>D.43%<br>3.所得溶液中,属于饱和溶液的是( )<br>A.①<br>B.②<br>C.③<br>D.④<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/f10e4ed490c3405fbe7b5f504d0e5d38/89E534C439DC6A42F92F60C4BC983148.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/d831abd070c84bcf90099a581085e573/1625C491FA41FCFF476AF16E9558EE8D.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>用下图装置可验证空气中<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>的含量。下列现象能表明<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>含量的是( )<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CC994681CB99E234E25D5FE8B45CE684.png"><br>A.集气瓶中产生大量白烟<br>B.红磷燃烧一段时间后熄灭<br>C.烧杯中的水倒吸进入集气瓶<br>D.集气瓶中水面最终上升至1处<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/6e518eb542924ef186f4f78c6638246b/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/1e8bc87a6ecc406fbcf985a6c2924ff6/A2D3166B57C83A518FBABA8C1DD76937.png"><br><br>※题型：单选题※知识点：单选题※试题难度：中等<br>实验研究铁锈蚀影响因素,记录如下、下列分析不正确的是( )<br><tbody><br>实验装置<br>序号<br>其他试剂<br>100s时<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>的含量<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/620521565E870017C3D8A1C9E627341C.png"><br>①<br>干燥剂<br>21%<br>②<br>10滴水<br>15%<br>③<br>10滴水和1.0g食盐<br>8%<br></tbody><br>A.②③中<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>含量减少表明铁已锈蚀<br>B.①②证明水对铁锈蚀有影响<br>C.②③证明食盐能加快铁锈蚀<br>D.①②③证明炭粉对铁锈蚀有影响<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/0530f92b073845efa84f7e024294efc6/01A39E48B8A67989A23F6887F26FCC64.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/55646281c5144ac6801fae9445728c21/C3B1DDF0907510B8C9D5E272E5729C46.png"><br><br>※题型：填空题※知识点：填空题※试题难度：容易<br>从<br>A<br>或<br>B<br>两题中任选一个作答,若两题均作答,按<br>A<br>计分。<br><tbody><br>A<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/69006AE9978DAE1FF1136A3E55851AD2.png"><br>的用途之一是<br>______<br>B<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/69006AE9978DAE1FF1136A3E55851AD2.png"><br>的俗名是<br>______<br></tbody><br><br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/166ca78d81d242c7826ebeb3ec2e8517/A89B1CC5327E9EC41AFA409BBBC6B169.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/acfebb362cd44c7884fef9cf2ededb0d/5981560A7FA0AF56DCCE0CD767413BAC.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br>我国提出<br>2060<br>年前实现碳中和,彰显了负责任大国的作为与担当。<br>1.现阶段的能源结构仍以化石燃料为主,化石燃料包括煤、______和天然气。<br>2.下列燃料在<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>中燃烧时,不会产生<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>的是______(填序号)。A.天然气B.氢气C.肼(<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/2102184E6537F16C30821812B89B9D6A.png"><br>)3.捕集、利用和封存<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>是实现碳中和的一种途径。矿物质碳化封存的反应之一是氧化镁与<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>反应生成碳酸镁,该反应的化学方程式为______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/cda1c4ed5d634a3f963fbf8b53606c7b/5029D5580BE133ED4FFAA0B66ABD8D30.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/4ce431bf613e40fcb0bc3c9c78873d2f/DB4052672D8069CB572AFCEFB6AE46F6.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>溶液常用作的消毒剂。<br>1.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>溶液属于______(填“混合物”或“纯净物”)。<br>2.<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>不稳定,易分解。<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>分解的化学方程式为______。3.用3%的<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/E947C2E36CD3B4692A2CC3A67A71F96C.png"><br>溶液对不同金属进行腐蚀性实验,结果如下:<br><tbody><br>金属种类<br>不锈钢片<br>铝片<br>铜片<br>腐蚀速度(mg/h)<br>0.001<br>0.010<br>0.404<br></tbody><br>下列金属制品用该溶液浸泡消毒时,最易被腐蚀的是______(填序号)。A.不锈钢锅B.铝盆C.铜火锅<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/48c1e518191b47f2ba71acd5a2f9d4d1/B962B7166614EF217F38C9753099A0BB.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/9c01ac6f93d44fdfb37da4f67d2cb0d7/4FC18A05A1227A0E05B9E973A2652AC4.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br>真空热还原法生产钙的主要转化过程如下:<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/85DFEC2904BE9ED05B4B70D36ECA3876.png"><br>1.石灰石的主要成分是______。2.Ⅱ中反应有两种产物,固体X一定含有氧元素和铝元素,从元素守恒角度说明理由______。3.装置中发生的是______(填“物理”或“化学”)变化。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/4051dabdac134c6b93ee58abc2b0f5af/6604A672FA3BBB5965D4A0BE39549F13.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/001604644d2649ea84370c7541b4c91b/23A0492904F92A6571E5EDEB8BE5F0F7.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br>高纯<br>CO<br>可用于半导体领域某些芯片的刻蚀,利用甲酸(<br>HCOOH<br>)制取高纯<br>CO<br>的主要流程如下:<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/7B49C1E8FBD55E1217E2E23DD9C0E34B.png"><br>1.甲酸中碳元素和氧元素的质量比为______。<br>2.反应塔中甲酸分解的微现示意图如下,在方框中补全另一种产物的微粒图示____。<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/25C7A712D69272769254CE23804E5E1E.png"><br> 3.反应塔中发生副反应产生微量<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>。洗涤器中加入NaOH溶液的目的是中和未反应的甲酸蒸气,并除去<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>,NaOH与<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>反应的化学方程式为______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/35a0cbb814334aa3bfe9e2d2d00af54d/AE6EF281EF83CA50DF5410A07D698A22.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/3141a84dec04463c895fac37eefc0cd5/9AE3D4C1B5AC7EB24DAD267A5256E199.png"><br><br>※题型：实验题※知识点：实验题※试题难度：较易<br>根据下图回答问题。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/42A0769E0FE5DA04F78DC4D6E1DEE2CB.png"><br>1.仪器a的名称是______。<br>2.加热<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/132CE5A4221DCE8F26C90950FF673643.png"><br>制取<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>的化学方程式为______。3.收集<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>的装置是______(填序号)。4.将带火星的木条放在瓶口,若观察到______,说明瓶中已充满<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/CE3FB2E68B350B28E5B76D176FE3FE33.png"><br>。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/f5cb96b6a2a34d5ebd0b8c04171585b8/3A621914655CE791BDB500872643305F.png"><br>解析<br>略<br>※题型：实验题※知识点：实验题※试题难度：中等<br>用下图实验(夹持仪器已略去)研究铁的性质。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/1FA3DE746803B21281EB65311C0298F2.png"><br>1.实验1,观察到蜡片熔化,说明铁具有的性质是______。<br>2.实验2,反应的化学方程式为______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/e66a8f9afee948d9ad581f84a060e3ea/B802DF3B1AD78A01ED3118191762E433.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/e093f2d690d84e4b95aeb15cd0c9a137/FA03E538793DC7E573BF301F5928E230.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br>下图是去除粗盐中难溶性杂质实验的三步操作。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/B2583E8D8C53146125B1C0C9968C532B.png"><br>1.三步操作的正确顺序是______(填序号)。2.B中,用璃棒不断搅拌的目的是______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/b7775c5fb84e4713abbbd2c2040f6117/D56E15CCE651172F0A8F5CC127013068.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/7734c221e3ed4c3a9ad81d5fe2eea7c4/8C8407753D607A9FA73A0CB01BDA138B.png"><br><br>※题型：填空题※知识点：填空题※试题难度：中等<br>用下图装置研究酸、碱的性质。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/FF8062A4A1816D438C9D5B798E4518DE.png"><br>1.向1中滴加<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/EFEBBDF3EA678C79CA2246E8BC6970BF.png"><br>溶液,观察到的现象是______。<br>2.向2、3中滴加无色酚酞溶液,溶液变红的是______(填序号);再向3中滴加NaOH溶液,NaOH与盐酸反应的化学方程式为______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/b994eb09827243059e95e8e6ceec721c/29D5E0B88BAB6CD584AC2FBDA7B0C81E.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/ec37543cc92f44b8b543cb8a020a7512/BFA6C24D058DCD3F603EC600A62A48D0.png"><br><br>※题型：实验题※知识点：实验题※试题难度：中等<br>用如图实验验证<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>的性质。<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/C1431963A82516AE98D58A2983F3AAAC.png"><br>1.实验室制取<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>的化学方程式为______。<br>2.观察到短蜡烛熄灭后,关闭K,片刻后长蜡烛熄灭,由此得到的结论是______。3.观察到纸花变红,由此并不能得出“<img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/3AB34B1B8224706C6E4369A324ED490A.png"><br>能与水发生化学反应”的结论,理由是______。<br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/1f1091c7b1dd4f4aa8ad02a29e125c14/E63F24DDA33DDDFB74113E8BDA39948E.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/8ab07adec5c947669fe4b26a5b032785/2CC8CFFC07E379D4FC740D17C9A3561C.png"><br><br>※题型：实验题※知识点：实验题※试题难度：中等<br>硬水加热时易产生水垢,很多工业用水需要对硬水进行软化处理。小组同学利用<br>1.5%<br>的肥皂<br>水比较水<br>的硬度。<br>(查阅资料)硬水含较多可溶性钙、镁化合物;软水不含或含较少可溶性钙,镁化合物。<br>Ⅰ<br>、探究水的硬度、肥皂水的用量与产生泡沫量的关系<br>(进行实验)向蒸馏水中加入<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/B24F7CDE6AD9E94EFD42E801F850ED99.png"><br>和<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/19DB00263A67B64F8C686CD794139E8F.png"><br>的混合溶液,配制两种不问硬度的硬水。<br>用蒸馏水和两种硬水完成三组实验,记录如下:<br><tbody><br>组别<br>第<br>组<br>第<br>组<br>第<br>组<br>实验操作<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/DE4BC4E2FA8113D96F6918AB71386C0C.png"><br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/ACDEDD2C53E2BDD932106012013DB14B.png"><br>实验序号<br>①<br>②<br>③<br>④<br>⑤<br>⑥<br>⑦<br>⑧<br>⑨<br>混合溶液用量<br>/<br>滴<br><br>x<br><br>肥皂水用量<br>/<br>滴<br><br><br>产生泡沫量<br>少<br>多<br>很多<br>无<br>少<br>多<br>无<br>无<br>少<br></tbody><br>(解释与结论)<br>(<br>)对比<br>②<br>和<br>⑧<br>可知,肥皂水能区分软水和硬水,依据的现象是<br>______<br>(<br>)设计第<br>组实验时,为控制水的硬度相同,<br>⑤<br>中<br>x<br>应为<br>______<br>(<br>)第<br>组实验的目的是<br>______<br>(<br>)由上述三组实验得到的结论是<br>______<br>Ⅱ<br>、比较不同水样的硬度<br>(进行实验)用四种水样完成实验,记录观察到泡沫产生时所需肥皂水的用量。<br><tbody><br>实验操作<br>水样<br>肥皂水用量<br>/<br>滴<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/7B38904EDACACB75027D64D4B7A5297A.png"><br>市售纯净水<br>煮沸后的自来水<br>自来水<br>湖水<br>14<br></tbody><br>(解释与结论)<br>(<br>)硬度最大的水样是<br>______<br>(<br>)由上述实验可知,能将自来水硬度降低的方法有<br>______<br>(<br>)继续实验,发现山泉水的硬度大于自来水的硬度,其实验方案为<br>______<br><br>答案<br><img src="https://picture2.zhihuicn.com/answer/2/5/2021/657b7899580d41018bb5afc960b222ea/61FC1CB9F644FB2B7960CFC3256BCE33.png"><br>解析<br><img src="https://picture2.zhihuicn.com/explain/2/5/2021/b7032c851f7a4000b3ccc8b91c752a7b/5681D61BB29BA13A66B461F952C8E357.png"><br><br>※题型：计算题※知识点：计算题※试题难度：较易<br>《天工开物》中记载了金属的冶炼技术。在锌的冶炼方法中,主要反应之一为<br><img src="https://picture2.zhihuicn.com/testImage/2/2021/7/22/A51B8108AB27B23DBFC923CAB877532A.png"><br>alig"
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