【单选题】已知反应4NH 3 +5O 2 4NO+6H 2 O,若反应速率分别用v(NH 3 )、v(O 2 )、v(NO)、v(H 2 O)表示,则下列正确的关系是( )
【单选题】在反应4NH 3 +5O 2 ═4M+6H 2 O中,M的化学式为( )
【单选题】已知在某密闭容器中发生反应 4NH 3 +5O 2 =4NO+6H 2 O,若反应速率分别用 υ(NH 3 )、υ(O 2 )、υ(NO)、υ(H 2 O)表示,则下列关系正确的是
【单选题】氨氧化制硝酸第一步是在铂催化剂存在下发生下列反应:4NH3+5O2=4NO+6H2O反应前NH3流量40mol/h,O2流量60mol/h,反应后气体中NH34mol/h,则出口气体中NO含量是下列哪个数值?
【单选题】已知反应4NH 3 +5O 2 ?4NO+6H 2 O,若反应速率分别用v (NH 3 )、v (O 2 )、v (NO)、v (H 2 O)(mol?L -1 ?min -1 )表示,则下列正确的关系是( )
A.
4 5 v (NH 3 )=v (O 2 )
B.
5 6 v (O 2 )=v (H 2 O)
C.
2 3 v (NH 3 )=v (H 2 O)
【单选题】I left very early last night, but I wish I______so early.
【单选题】From May 6, pedestrians(行人) 10 yuan if they run red lights, according to Beijing traffic authorities.
【单选题】From paragraph 6 we may infer that one of the effective measures suggested by Ludnik to pre-vent children from being obese would be___________
A.
not to permit them to watch TV at all
B.
to tell them to spend less time watching TV
C.
to turn off TV when they are in front of TV sets
D.
to calculate accurately the time that a child spends watching TV
【单选题】已知反应4NH 3 +5O 2 4NO+6H 2 O,若在反应开始后5s~10s之间的反应速率分别用v(NH 3 )、v(O 2 )、v(NO)、v(H 2 O)表示,则下列判断正确的关系是( )。