Question

除去下列各物質(zhì)中混有的少量雜質(zhì)，所用試劑不正確的是

序號                   物 質(zhì)                     雜  質(zhì)                   所 用 試 劑

A                         N₂                            O₂                            灼熱的銅網(wǎng)

B                          CO₂                         H₂O                         濃硫酸

C                          CaO                         CaCO₃                     適量的稀鹽酸

D                         NaCl溶液              Na₂CO₃                   適量的稀鹽酸

 

Answer 1

【答案】

C

【解析】

序號          物質(zhì)             所用試劑                     是否反應(yīng)                                                        是否可行

A                N₂                 灼熱的銅網(wǎng)                否                                                                     可

                  O₂                                                       Cu+O₂→CuO                                                 

B                CO₂               濃硫酸                         否                                                                     可

                  H₂O                                                    被濃硫酸銅吸收                                          

C                CaO              適量稀鹽酸                CaO+HCl→CaCl₂+H₂O                                   否

                  CaCO₃                                                CaCO₃+HCl→CaCl₂+H₂O+CO₂↑                 

D                NaCl             適量稀鹽酸                否                                                                     可

                  Na₂CO₃                                               Na₂CO₃+HCl→NaCl+H₂O+CO₂↑                

考點：除雜

點評：除雜要求能除去雜質(zhì)并且不能增加新雜質(zhì)。