it's march 21st.

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• FeS的电离中c(Fe+)*c(s2-)=6.25*10^-18,又知溶液中,[c(H+)]^2*c(S2-)=1*10^-22现将适量的FeS,投入饱和溶液中,要使溶液的c(Fe2+)达到1mol/L,应调节溶液的PH为多少?
• 填标点⑨听了这番有趣的解释,我对这种树木产生出一种sǜ rán qǐ jìng ( )的感情.它既能生在土质肥沃□气候相宜的美丽风景区□又能繁殖于干燥贫瘠□漫漫沙流的不毛之地□它在湖光山影□花红柳绿的秀丽处所□风姿飘洒□落落大方□现出一派bǜ bēi bǜ kàng( )的仪表□它在满目黄沙□寸草不生的古漠□轻声慢语□谦和内秀□没有一点傲然超众□gū fāng zì shǎng( )的神情□我爱旅行家树的所有具有的这种品质□离开非洲时,我曾想带回一株旅行家树的幼苗,移植于自己的庭院里,后来又作罢,心想：倒莫如把旅行家树的品质,移植于自心中.
• FeS饱和溶液中c(Fe2+)c(S2与c（H+）*c(OH-)=Kw类似,FeS饱和溶液中c（Fe2+)*c(S2-)=Ksp.常温下Ksp=8.1*10-17.理论上FeS的溶解度为?而事实上其浓度远大于这个数值,其原因可能是?
• Fe2+和S2-反应是生成FeS还是发生双水解?Fe2+和S2-反应是生成FeS沉淀还是发生双水解生成Fe(OH)2和H2S?为什么不发生双水解?FeS溶解度小于Fe(OH)2,H2S会和Fe(OH)2反应生成FeS?
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