皮皮学，免费搜题
登录
搜题
【简答题】
某同学进行试验探究时，欲配制1．0molL -1 Ba(OH) 2 溶液，但只找到在空气中暴露已久的Ba(OH) 2 ·8H 2 O试剂（化学式量：315）。在室温下配制溶液时发现所取试剂在水中仅部分溶解，烧杯中存在大量未溶物。 为探究原因，该同学查得Ba(OH) 2 ·8H 2 O 部分溶解度数据，见下表： 温度 283K 293K 303K 溶解度（g/100g H 2 O） 2．5 3．9 5．6 （1）烧杯中未溶物仅为BaCO 3 ，理由是 。 （2）假设试剂由大量Ba(OH) 2 ·8H 2 O和少量BaCO 3 组成，设计试验方案，进行成分检验，在答题纸上写出实验步骤、预期现象和结论。（不考虑结晶水的检验；室温时BaCO 3 饱和溶液的pH＝9．6） 限选试剂及仪器：稀盐酸、稀硫酸、NaOH溶液、澄清石灰水、pH计、烧杯、试管、带气管、滴管 实验步骤 预期现象和结论 步骤1：取适量试剂于洁净烧杯中，加入足量蒸馏水，充分搅拌，静置，过滤，得滤液和沉淀。 ＃＃＃＃＃＃ 步骤2：取适量滤液于试管中，滴加稀硫酸。 _______________________ 步骤3：取适量步骤1中的沉淀于试管中， , 连接带气管将产生的气体导入澄清石灰水中。 _______________________ ______________________ 步骤4：取步骤1中的滤液于烧杯中,______________________________ _______________________,说明该试剂中含有Ba(OH) 2 。 （3）将试剂初步提纯后，准确测定其中Ba(OH) 2 ·8H 2 O的含量。 实验如下：①配制250 mL 约0．1mol·L -1 Ba(OH) 2 ·8H 2 O溶液：准确称取w克试样，置于烧杯中，加适量蒸馏水，搅拌，将溶液转入 ，洗涤，，摇匀． ②滴定：准确量取25．00ml所配制Ba(OH) 2 溶液于锥形瓶中，滴加指示剂，将 （填“0．020”、“0．05”、“0．1980”或“1．5”）molL -1 盐酸装入50ml酸式滴定管，滴定至终点，记录数据。重复滴定2次。平均消耗盐酸Vml。 （4）室温下， (填“能”或“不能”) 配制1．0 mol·L -1 Ba(OH) 2 溶液，说明理由________________________________________________________________________________________．
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
.
..
皮皮学刷刷变学霸
举一反三
【简答题】听录音，选择你所听到的句子。 (     ) 1. A. This is my father. B. This is my friend. C. This is my grandpa. (     ) 2. A. The fish is nice. B. The fish is big. C. The picture is nice. (     ) 3. A. I have forty penc...
查看完整题目与答案
【简答题】已知X与Y的相关系数Corr(X,Y)=0.25,则Corr(2X+3,4Y+8)=____。
查看完整题目与答案
【简答题】阅读理解。 1. This is _______ for Kesington Hotel in London. A. a notice B. a postcard C. a picture D. an advertisement 2. A single room and a double room in Kesington Hotel cost _______ each night. A. ￡ 6...
查看完整题目与答案
【简答题】何谓自动加速现象?并解释产生的原因。
查看完整题目与答案
【简答题】阅读理解 Now, please look at this picture. This girl is my sister. Her name is Sally! She is l3 years old. She is in Class Two, Grade Seven. This boy is aunt's son. He is my cousin. His name is Jeff. He i...
查看完整题目与答案
【单选题】What is the correct speed input to an ARPA used for traffic surveillance?
A.
speed from GPS
B.
speed from Doppler
C.
ground speed
D.
speed through water
查看完整题目与答案
【简答题】听材料，回答问题。 1. What picture is the woman showing the man? A. A picture of the Great Wall. B. A picture of Beijing Zoo. C. A picture of the History Museum. 2. How many places did the woman visit besides ...
查看完整题目与答案
【简答题】自动加速现象产生的原因是什么?
查看完整题目与答案
【单选题】A recent spate of launching and operating mishaps with television satellites led to a corresponding surge in claims against companies underwriting satellite insurance. As a result, insurance premiums ...
A.
Since the risk to insurers of satellites is spread over relatively few units, insurance premiums are necessarily very high.
B.
When satellites reach orbit and then fail, the causes of failure are generally impossible to pinpoint with confidence.
C.
The greater the performance demands placed on satellites, the more frequently those satellites break down.
D.
Most satellites are produced in such small numbers that no economies of scale can be realized.
E.
Since many satellites are built by unwieldy international consortia, inefficiencies are inevitable.
查看完整题目与答案
【简答题】完型填空。 A picture 1 on my desk. This is a picture 2 Tom’s family(家). The man is Tom’s 3 . A 4 is behind Tom. She is 5 mother. 6 teachers. A girl is 7 the picture, too. She is Tom’s sister. 8 name is Amy...
查看完整题目与答案
相关题目：
【简答题】听录音，选择你所听到的句子。 (     ) 1. A. This is my father. B. This is my friend. C. This is my grandpa. (     ) 2. A. The fish is nice. B. The fish is big. C. The picture is nice. (     ) 3. A. I have forty penc...
查看完整题目与答案
【简答题】已知X与Y的相关系数Corr(X,Y)=0.25,则Corr(2X+3,4Y+8)=____。
查看完整题目与答案
【简答题】阅读理解。 1. This is _______ for Kesington Hotel in London. A. a notice B. a postcard C. a picture D. an advertisement 2. A single room and a double room in Kesington Hotel cost _______ each night. A. ￡ 6...
查看完整题目与答案
【简答题】何谓自动加速现象?并解释产生的原因。
查看完整题目与答案
【简答题】阅读理解 Now, please look at this picture. This girl is my sister. Her name is Sally! She is l3 years old. She is in Class Two, Grade Seven. This boy is aunt's son. He is my cousin. His name is Jeff. He i...
查看完整题目与答案
【单选题】What is the correct speed input to an ARPA used for traffic surveillance?
A.
speed from GPS
B.
speed from Doppler
C.
ground speed
D.
speed through water
查看完整题目与答案
【简答题】听材料，回答问题。 1. What picture is the woman showing the man? A. A picture of the Great Wall. B. A picture of Beijing Zoo. C. A picture of the History Museum. 2. How many places did the woman visit besides ...
查看完整题目与答案
【简答题】自动加速现象产生的原因是什么?
查看完整题目与答案
【单选题】A recent spate of launching and operating mishaps with television satellites led to a corresponding surge in claims against companies underwriting satellite insurance. As a result, insurance premiums ...
A.
Since the risk to insurers of satellites is spread over relatively few units, insurance premiums are necessarily very high.
B.
When satellites reach orbit and then fail, the causes of failure are generally impossible to pinpoint with confidence.
C.
The greater the performance demands placed on satellites, the more frequently those satellites break down.
D.
Most satellites are produced in such small numbers that no economies of scale can be realized.
E.
Since many satellites are built by unwieldy international consortia, inefficiencies are inevitable.
查看完整题目与答案
【简答题】完型填空。 A picture 1 on my desk. This is a picture 2 Tom’s family(家). The man is Tom’s 3 . A 4 is behind Tom. She is 5 mother. 6 teachers. A girl is 7 the picture, too. She is Tom’s sister. 8 name is Amy...
查看完整题目与答案