一种可作为绿色能源的物质X,其燃烧的化学反应为:X+2O2→CO2+2H2O,判 发布时间:2017-07-04 09:55 │ 来源:www.tikuol.com 题型:选择题 问题: 一种可作为绿色能源的物质X,其燃烧的化学反应为:X+2O2→CO2+2H2O,判断X的化学式为( )A.H2B.CH4C.CH3OHD.C2H5OH
题型:选择题 用氢氧化钠溶液测定某硫酸溶液溶质的质量分数.实验如下:取25g该硫酸溶液,加入到烧杯中,然后把50g质量分数为10%的氢氧化钠溶液不断滴入烧杯中,同时用电子PH计不断读取反应时的PH,得出如图所示的关系,求;(1)该硫酸溶液溶质的质量分数.(2)配制500g上述硫酸溶液,所需质量分数为98%的硫酸溶液的质量. 查看答案
题型:选择题 信息匹配(1分X5=5分)Shanghai is not only the largest seaport city and economic(经济的) center of China, but also the most modern and fashionable international(国际的) city as well. It lies in the east of China and faces the East China Sea.With a long history, there are many interesting places in Shanghai. It is really a good place to go on vacation. Also being a modern city, Shanghai is a good place to go shopping. You can see many fashionable things there. Walking along Nanjing Road and Huaihai Road, you will have a chance to follow the latest fashion.I think the best time to Shanghai is in summer. But don’t forget to bring your umbrella because it rains a lot here in summer.Welcome to Shanghai!The location(地点) of Shanghai1. It lies in _____________ and faces the East China Sea.What to do in Shanghai?2. Visit _____________.3. _____________________________.Two famous roads in Shanghai4. ________________ and Huaihai Road.What’s the weather like in summer in Shanghai?5. It___________________ in summer. 查看答案