Question

除去下列各物质中混有的少量杂质，所用试剂不正确的是

序号                   物 质                     杂  质                   所 用 试 剂

A                         N₂                            O₂                            灼热的铜网

B                          CO₂                         H₂O                         浓硫酸

C                          CaO                         CaCO₃                     适量的稀盐酸

D                         NaCl溶液              Na₂CO₃                   适量的稀盐酸

 

Answer 1

【答案】

C

【解析】

序号          物质             所用试剂                     是否反应                                                        是否可行

A                N₂                 灼热的铜网                否                                                                     可

                  O₂                                                       Cu+O₂→CuO                                                 

B                CO₂               浓硫酸                         否                                                                     可

                  H₂O                                                    被浓硫酸铜吸收                                          

C                CaO              适量稀盐酸                CaO+HCl→CaCl₂+H₂O                                   否

                  CaCO₃                                                CaCO₃+HCl→CaCl₂+H₂O+CO₂↑                 

D                NaCl             适量稀盐酸                否                                                                     可

                  Na₂CO₃                                               Na₂CO₃+HCl→NaCl+H₂O+CO₂↑                

考点：除杂

点评：除杂要求能除去杂质并且不能增加新杂质。