【单选题】若烷烃分子中C-C键能为345.6kJ/mol,则烯烃分子中烯键C=C的键能应是( )kJ/mol。
【单选题】若烷分子中C-C键能为345.6kJ/mol,则烯烃分子中烯键 的键能应该是多少 kJ/mol?
【单选题】If a business owner decided to expand her business but rather than borrowing money from a bank used her own funds, then
A.
she would be unable to earn a normal profit.
B.
there is no cost associated with the expansion.
C.
she would forego the opportunity to earn interest on the money.
D.
the amount of her funds she used is an explicit cost.
E.
the amount of her funds she used is part of her normal profit.
【单选题】若烷分子中 C - C 键能为 345.6kJ / mol ,则烯烃分子中烯键的键能应该是多少 kJ / mol ? A .等于 2 × 345.6 B .大于 2 × 345.6 C .小于 2 × 345.6 D .小于 345.6
【单选题】现有Wg某不饱和链烃R(R分子中只含单键和双键),R能与VL(标准状况)氢气恰好完全反应,生成烷烃。若R的相对分子质量为M,阿伏加德罗常数为N A ,则lmol R中含有双键数目为( )
【简答题】烷基取代苯( )可以被酸性KMnO 4 溶液氧化生成 ,但若烷基R中直接与苯环连接的碳原子没有C—H键,则不容易被氧化得到 。现有分子式是C 11 H 16 的烷基一取代苯,则它可以被氧化成为 的同分异构体共有 ▲ 种,并写出一种不能被氧化成为 的同分异构体的结构简式 ▲ 。
【简答题】烷基取代苯( )可以被酸性KMnO 4 溶液氧化生成 ,但若烷基R中直接与苯环连接的碳原子没有C-H键,则不容易被氧化得到 .现有分子式是C 11 H 16 的烷基一取代苯,则它可以被氧化成为 的同分异构体共有______种,并写出一种不能被氧化成为 的同分异构体的结构简式______.
【单选题】It is tree about the media mentioned in the passage that they ______.
A.
used to sell and buy each other in great numbers
B.
are trading each other in greater numbers today
C.
used to be controlled by two networks -- ABC and NBC
D.
have stopped the trend of acquisitions in the 1990s
【单选题】下列说法中正确的是
B.
烷烃分子中,相邻的三个碳原子有可能在同一条直线上
C.
每个碳原子的化合价都已“饱和”,碳原子之间只以单键相结合的链烃一定是烷烃
D.
分子组成上相差一个或若干个CH 2 原子团的物质,互为同系物