问题详情:参考下表键能数据,估算晶体硅在氧气中燃烧生成的二氧化硅晶体的热化学方程式:Si(s)+O2(g)===SiO2(s)中,ΔH的值为()化学键Si—OO===OSi—SiSi—ClSi—C键能/kJ·mol-1460498.8176360347A.-989.2kJ·mol-1 B.+989.2kJ·mol-1C.-61.2kJ·mol-1 ...
2021-10-29 11204
问题详情:Alice was beginning to get very 16 and her sister were17 under the trees Her sister was18, but Alice had nothing to do. Once or twice she 19 into her sister's 20 , but it had no pict...
2020-12-17 13889
问题详情:有关键能数据如下表所示:则晶体硅在氧气中燃烧的热化学方程式为Si(s)+O2(g)===SiO2(s)ΔH=-989.2kJ·mol-1,则x的值为()A.460 B.920 C.1165.2 D.423...
2020-03-05 9781
问题详情:Thebackpack beLinda’s.It beGrace’s.Isawitatherhomebefore.A.mustn’t,must B.can’t,must C.maynot,can D.could,might【回答】B知识点:情态动词题型:选择题...
2020-12-10 15657
问题详情:SiCl4在室温下为无*液体,易挥发,有强烈的刺激*气味。工业上,提纯粗硅的原理如下: (1)已知:①Si(s)+4HCl(g)SiCl4(g)+2H2(g)△H1=-241kJ·mol-1②Si(s)+3HCl(g)SiHCl3(g)+H2(g)△H2=-210kJ·mol-1③3SiCl4(g)+2H2(g)+Si(s)4SiHCl3(g)△H3=-akJ·mol-1a= 。...
2022-08-10 24138
问题详情:已知:①1 mol晶体硅中含有2molSi—Si键。②Si(s)+O2(g)===SiO2(g)ΔH,其反应过程与能量变化如图所示。③化学键 Si—OO===OSi—Si断开1mol共价键所需能量/kJ460500176下列说法中正确的是()A.晶体硅光伏发电是将化学能转化为电能 B.二氧化硅稳定*小于硅的稳定*C...
2019-05-08 25100
问题详情:下列说法正确的是( )A.SiO2(s)+2C(s)=Si(s)+2CO(g)在常温下不能自发进行,则该反应的△H>0B.一定条件下,将0.5molN2(g)和1.5molH2(g)置于密闭的容器中充分反应生成NH3(g),放热19.3kJ,其热化学方程式为:N2(g)+3H2(g)2NH3(g) △H=-38.6kJ·mol-1C.C(s)+H2O(g)CO(g)+H2...
2020-08-28 13266
问题详情:300℃ 950℃ 制造太阳能电池需要高纯度的硅,工业上制高纯硅常用以下反应实现①Si(s)+3HCl(g)======SiHCl3(g)+H2(g) ②SiHCl3+H2======Si+3HCl对上述两个反应的下列叙述中,错误的是( )A.两个反应都是置换反应 B.反应②不是置换反应...
2021-09-10 18404