问题 选择题

试管中盛有黑色粉末,将其加强热,粉末变为红色,同时产生无色气体,该气体能使澄清的石灰水变浑浊,则该黑色粉末可能是(  )

A.木炭粉

B.四氧化三铁

C.氧化铜

D.木炭粉和氧化铜

答案

气体能使澄清的石灰水变浑浊,所以该气体是二氧化碳,常见的红色的粉末有红磷,铜,氧化铁,黑色粉末加强热会生成红色粉末和二氧化碳,所以红色粉末是铜,黑色粉末中含有氧化铜和木炭,经过验证各物质都满足转换关系,所以黑色粉末是木炭和氧化铜的混合物,

故选D.

写作题

看图写话。

                           

1. enjoy, by                          2. victory                             3. come home, in ten minutes

1.                                                                                                                             

2.                                                                                                                             

3.                                                                                                                             

                                                        

4. remember, light, when, leave                                          5. trees, cut down

4.                                                                                                                              

5.                                                                                                                              

判断题