题目

I am going to (sing/sings) a song for my mother this evening. 答案：【1】sing已知下列两个热化学方程式：H2(g)+ O2(g)=H2O（1） △H=－285.8 kJ·mol－lC3H8(g)+5O2(g)=4H2O(l)+3CO2(g) △H =－2220.0kJ·mol－l（1）相同条件下，实验测得H2和C3H8的混合气体共5 mol，完全燃烧生成液态水时放出热量6264.5 kJ，则混合气体中H2和C3H8的体积比为___________。（2）已知：H2O（1）=H2O(g) △H =44.0kJ·mol－l．写出丙烷燃烧生成CO2和气态水的热化学方程式_______________。