题目

Sb2O5是一种重要的阻燃剂。用X来生产该阻燃剂的化学方程式为: X + 2H2O2 ==Sb2O5+2H2O，根据质量守恒定律，推断X的化学式为A．SbO2 B．Sb2O3 C．HSbO3 D．H3SbO4 答案：【答案】B 【解析】 试题分析：在化学反应中遵循质量守恒定律，即反应前后元素的种类不变，原子的种类、个数不变．比较反应前后的原子的种类和个数可以完成对X的化学式的推断．从X+2H2O2=Sb2O5+2H2O看，反应前有4个氢原子、4个氧原子，反应后有2个Sb原子、4个H原子、7个O原子；根据质量守恒定律，可If you __________ my advice, you __________ your failure now. You __________ your victory.A. took; wouldn't cry over; would celebrateB. had taken; wouldn't have cried over; would have celebratedC. had taken; aren't crying over; are celebratingD. had taken; wouldn't be crying over; would be celebrating