学英语环球阅读周报八年级十五期答案

书面表达One possible version:NOTICEA sports meeting will be held in the playground of our school from next Thursday to FridayAs you know, the pressure of study is very heavy now, especially for those senior 3. So the purpose of the sports meeting is to letevery student get relaxed, as a result of which we students can live happily and heal thilyEveryone is welcome to take part in it. Those who perform excellently at the sports meeting will get prizes. But don' t take theresults so serously because taking part is more important than the result. Good luck to everyone!

18,(1)增大固体表面积,加快浸出速率(1分)(2)烧杯、分液漏斗(2分)(3)2InSb+ 12HNO,(ie)= In, O3+ Sh: O,+12NO2↑+6H:((2分)(4)HNO32(2分)3:1(2分)(5)7.7×10-(2分)【解析】(1)硬锌粗渣浸出前需进行球磨成粉,其原因是增大固体表面积,加快浸出速率。(2)浸出液Ⅱ中加入有机溶剂,操作Ⅱ后得到有机相和水溶液.故操作Ⅱ为萃取分液,需要的玻璃仪器有烧杯、分液漏斗。3)“氧化浸出”过程中,浓硝酸可将InSb(Sb为-3价)转化为In2O3和Sb2O3,同时释放出红棕色气体NO2,浓硝酸将InSb氧化.Sb的化合价从一3价升高为+3价,根据得失电子守恒、元素守恒配平该反应的化学方程式:2lnSb+12HNO3(浓)=In2O3+Sb2O+12NO2↑+6H2O。(4)H2O2含有极性共价键和非极性共价键, NaCIO含有极性共价键和离子键,HNO3只含有极性共价键,则三种物质中只含有极性共价键的物质是HNO2;H2O作氧化剂时,还原产物为水,则1molH:O:得2mol电子, NaCIo3作氧化剂时,被还原为CI-,则1molNaCI(3得到6mol电子,“氧化浸出”过程中,若分别使用H2O2、 Naclo3作氧化剂,转移电子的数目相同时则消耗二者的物质的量之比为3:15)该反应的化学平衡常数K=c(H+)c(In")((HT)C3(OHK(10-14)2c(In+)c(OH)K-[n(OH)3=1.3×10=7.7×10-6

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