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某石灰厂需要测定石灰石样品中CaCO3的质量分数．小刚设计了图1所示装置来完成实验（杂质不与酸反应）：（1）仪器①的名称是 ．A装置中反应的化学方程式是 （2）c装置应当选择图2，I、Ⅱ中的...
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某同学对实验室中失去标签的石灰石样品进行纯度样品中碳酸钙的质量分数测定取这种石灰石样品12.5g加入
为了测定石灰石中碳酸钙的质量分数某兴趣小组的同学称取石灰石样品12.5g高温煅烧至质量不再改变称得剩
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某石灰厂需要测定产品生石灰中杂质杂质只含CaCO3的质量分数小刚进行了如下图实验请计算1生成CO2气
为测定某石灰石矿中碳酸钙的含量现称取12.5g石灰石矿样品与足量的稀盐酸反应杂质不溶于水也不参与反应
25g石灰石杂质不参加反应也不溶于水与73g稀盐酸恰好完全反应生成CO2质量为8.8g计算1石灰石中
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为测定某石灰石样品中碳酸钙的质量分数取22.2g石灰石样品放入盛有146g稀盐酸的烧杯中石灰石中的碳
为测定石灰石样品中碳酸钙的质量分数将10g石灰石样品放入烧杯中加入稀盐酸至不再产生气泡为止石灰石中的
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碳酸钙是牙膏中常用的摩擦剂可用石灰石作原料制得某牙膏厂现有一批石灰石样品为探究所含碳酸钙的质量高温煅
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BagsofLove LastyearIwasassignedtoworkatanofficenearmymother'shousesoIstayedwithherforamonth.DuringthattimeIhelpedoutwiththehouseworkandcontributedtothegroceries. AfterlessthanaweekIstartednoticingthatthegrocerieswererunningoutprettyquickly﹣wewerealwayssuddenlyoutofsomething.1wonderhowmymumcouldconsumethemsoquicklyIbeganobservingherdailyroutinefortwoweeks.TomysurpriseIfoundthatshewouldpackapaperbagfullofcannedgoodsandheadouteverymorningataboutnine.EventuallyIdecidedtofollowherand2happenedtrulyamazedme.Shewastakingthefoodtotherefugeecampin3shedistributedittochildren. Iaskedaroundandfoundoutthatmymumwasverywellknowninthearea.Thekidswereveryfriendlywithherandevenlookeduptoherasifshe4theirownmother.Thenit5hitme﹣shywouldshemotwanttotellmeaboutwhatshe6do?WassheworriedabouthowIwouldreactorthatIwouldstop7buythegroceriesifIfoundout? WhenshegothomeItoldheraboutmydiscovery.8shecouldreactIgaveherabighugandtoldhershedidn'tneedtokeepitasecret9me.Shetoldmethatsomeofthechildrenlivedwithanolderladyinashelterwhileotherssleptonthestreets.Foryearsmymumhasbeenhelpingoutbygivingthemwhateverfoodshecouldspare.Iwassoimpressedby10selflessshewas.
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常温时向20mL0.1mol•L﹣1的CH3CH2COOH溶液中滴加0.1mol•L﹣1的NaOH溶液溶液的pH与滴加NaOH溶液体积V的关系如图所示．下列说法正确的是
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