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【单选题】
已知 C—H 键的键力常数 5.0 N/cm ,则 C—H 振动吸收峰频率为
A.
1523 cm -1
B.
2523 cm -1
C.
2045 cm -1
D.
3045 cm -1
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【简答题】设阿伏加德罗常数为6.02×1023mol-1．下列关于1molH2O的叙述正确的是（ ）
A.
含有1molH2
B.
在标准状况下体积为22.4L
C.
含有6.02×1023个水分子
D.
质量为18g/mol
【单选题】已知下列单键伸缩振动中 C-C C-N C-O 键力常数 k /(N·cm -1 ) 4.5 5.8 5.0 吸收峰波长 λ/μm 6 6.46 6.85 则 C-C, C-N, C-O 键振动能级之差 ⊿ E 顺序为 ( )
A.
C-C > C-N > C-O
B.
C-N > C-O > C-C
C.
C-C > C-O > C-N
D.
C-O > C-N > C-C
【单选题】用NA表示阿伏加德罗常数的值．下列叙述正确的是（ ）
A.
在2升2mol/L的（NH4）2SO4溶液中所含的NH4+的数目是8NA
B.
常温常压下，2molCaC2晶体中含有的阴离子数为2NA
C.
14gN2和CO的混合气体含有的分子数目为0.5NA
D.
标准状况下，11.2L庚烷完全燃烧后生成的CO2分子数为3.5NA
【单选题】Passage One Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurem...
A.
Newton and Einstein had similar opinions on the speed of gravity
B.
the author of the passage is in favor of Einstein’s thought about the speed of gravity
C.
astronomers think that both Newton and Einstein were wrong on the speed of gravity
D.
Newton’s thought about the gravitational effect is out of date
【单选题】Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurement yet of Newton’s gravit...
A.
two things far apart might vibrate in unison
B.
the ripples in space-time are only imagined
C.
there exist gravitational waves
D.
abrupt, violent cosmic s lead to gravitational waves
相关题目：
【简答题】设阿伏加德罗常数为6.02×1023mol-1．下列关于1molH2O的叙述正确的是（ ）
A.
含有1molH2
B.
在标准状况下体积为22.4L
C.
含有6.02×1023个水分子
D.
质量为18g/mol
【单选题】若（x+a）（x+b）=x2+5x+6，则常数a，b的值可能是（ ）
A.
a=2，b=3
B.
a=-2，b=3
C.
a=2，b=-3
D.
a=-2，b=-3
【单选题】已知下列单键伸缩振动中 C-C C-N C-O 键力常数 k /(N·cm -1 ) 4.5 5.8 5.0 吸收峰波长 λ/μm 6 6.46 6.85 则 C-C, C-N, C-O 键振动能级之差 ⊿ E 顺序为 ( )
A.
C-C > C-N > C-O
B.
C-N > C-O > C-C
C.
C-C > C-O > C-N
D.
C-O > C-N > C-C
【单选题】主要影响片剂中药物吸收的剂型因素不包括
A.
片剂的处方组成
B.
包装材料
C.
片剂的崩解、溶出和释放
D.
片剂制备工艺
E.
药物的pKa及脂溶性
【单选题】用NA表示阿伏加德罗常数的值．下列叙述正确的是（ ）
A.
在2升2mol/L的（NH4）2SO4溶液中所含的NH4+的数目是8NA
B.
常温常压下，2molCaC2晶体中含有的阴离子数为2NA
C.
14gN2和CO的混合气体含有的分子数目为0.5NA
D.
标准状况下，11.2L庚烷完全燃烧后生成的CO2分子数为3.5NA
【单选题】图示简支梁EI = 常数，梁跨中截面的竖向位移为：（ ）
A.
B.
C.
D.
【单选题】万有引力常数最早是()测定的。
A.
牛顿
B.
卡文迪什
C.
拉瓦锡
D.
开普勒
【单选题】能够增加肾小管对磷的重吸收的是（）
A.
雌激素
B.
维生素D
C.
甲状旁腺素
D.
甲状腺素
E.
高血钙
【单选题】Passage One Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurem...
A.
Newton and Einstein had similar opinions on the speed of gravity
B.
the author of the passage is in favor of Einstein’s thought about the speed of gravity
C.
astronomers think that both Newton and Einstein were wrong on the speed of gravity
D.
Newton’s thought about the gravitational effect is out of date
【单选题】Gravity is a slippery beast. We don’t know how strong it is, how it works or how fast its effects move. But this year we made progress. October saw the most accurate measurement yet of Newton’s gravit...
A.
two things far apart might vibrate in unison
B.
the ripples in space-time are only imagined
C.
there exist gravitational waves
D.
abrupt, violent cosmic s lead to gravitational waves
【判断题】 地面吸收太阳短波辐射，升温，放射长波辐射。（ ）
A.
正确
B.
错误