Do you still remember the third video you watched in Lesson Two this unit? What should the passenger do with the prohibited item?
A. Save it.
B. Sell it.
C. Abandon it.
Deposit it.
查看答案
Choose the suitable sentences while asking people for an order.
Are you ready to order?
B. I think you’ll like it.
C. What can I get you?
D. It’s a kind of spicy.
某反应在一定条件下平衡的转化率为25%,当有催化剂存在时,其转化率应当()25%。
A. 大于
B. 小于
C. 等于
D. 大于或小于
下列对于催化剂特征的描述中,不正确的是 () 。
A. 催化剂只能改变反应达平衡的时间,对已达平衡的反应无影响
B. 催化剂在反应前后自身的化学性质和物理性质均不变
C. 催化剂不影响平衡常数
D. 催化剂不能实现热力学上不能发生的反应
已知下列反应的平衡常数:(1)H2(g)+S(s)=H2S(s)K1(2)S(s)+O2(g)=SO2(g)K2则反应H2(g)+ SO2(g)= O2(g)+ H2S(g)的平衡常数为( )
A. K1+K2
B. K1-K2
C. K1.K2
D. K1/K2