_______ by keeping down costs will Power Data hold its advantage over other companies. A. Only B. Just C. Still D. Yet 答案:A 解析: 从will Power Data hold可知句子用的是部分倒装语序,只有only+状语位于句首时句子才用倒装结构。其他几个词无此用法。
25℃,101 k Pa时,强酸与强碱的稀溶液发生中和反应生成1 mol水时所放出的热量约为57.3 kJ/mol;辛烷的燃烧热为5518 kJ/mol.下列热化学方程式书写正确的是
A.
CH3COOH(aq)+NaOH(aq)CH3COONa(aq)+H2O(l) ΔH=-57.3 kJ/mol
B.
KOH(aq)+H2SO4(aq)K2SO4(aq)+H2O(l) ΔH=-57.3 kJ/mol
C.
2C8H18(g)+25O2(g)16CO2(g)+18H2O(1) ΔH=-11036 kJ/mol
D.
C8H18(l)+O2(g)8CO2(g)+9H2O(g) ΔH=-5518 kJ/mol