[题目]为了验证木炭可被浓H2SO4氧化成CO2.选用如图所示仪器组装成实验装置:(1)如按气流由左向右流向.连接上述装置的正确顺序是: 接 . 接 . 接 .(2)仪器乙.丙应有怎样的实验现象才表明已检验出CO2?乙中 .丙中 .(3)丁中酸性KMnO4溶液的作用是 .(4)写出甲中反应的化学方程式 . 题目和参考答案——青夏教育精英家教网—

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【题目】为了验证木炭可被浓H2SO4氧化成CO2，选用如图所示仪器(内含物质)组装成实验装置：

(1)如按气流由左向右流向，连接上述装置的正确顺序是(填各接口字母)：________接________，________接________，________接________。

(2)仪器乙、丙应有怎样的实验现象才表明已检验出CO2?

乙中________________________，丙中________________________。

(3)丁中酸性KMnO4溶液的作用是__________________________________________。

(4)写出甲中反应的化学方程式____________________________________________。

【答案】(1)A F E C D B

(2)澄清石灰水变浑浊品红溶液未褪色

(3)吸收SO2

(4)C+2H2SO4(浓)CO2↑+2SO2↑+2H2O

【解析】木炭与浓硫酸加热反应生成CO2、SO2和H2O。其中CO2、SO2在化学性质上的相同点都是酸性氧化物，都跟澄清石灰水中的Ca(OH)2反应，使澄清石灰水变浑浊，这会干扰CO2的鉴别。SO2和CO2在化学性质上的明显不同点是SO2有漂白性和强的还原性，而CO2都没有。所以，在鉴别CO2时，首先用酸性KMnO4溶液将SO2氧化除去，再用品红溶液检验是否被完全除去，最后用澄清石灰水检验CO2的存在，是一种确认CO2存在的好方案。

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