【单选题】There will be an important English lecture at 14:30 this Sunday afternoon. (就划线部分提问)
A.
When will there be an important English lecture this Sunday afternoon?
B.
What time will there be an important English lecture this Sunday afternoon?
C.
What time is there an important English lecture this Sunday afternoon?
【判断题】KH2PO4水溶液的质子条件为:[H+]+[H3PO4] = [H2PO4-] + [HPO42-] + 2[PO43-] + [OH-]
【单选题】There will be an important English lecture at 14:30 this Sunday afternoon. (就划线部分提问)
A.
When will there be an important English lecture this Sunday afternoon?
B.
What time will there be an important English lecture this Sunday afternoon?
C.
What time is there an important English lecture this Sunday afternoon?
【简答题】计算0.1mol.L-1K2HPO4、KH2PO4、K3PO4溶液的pH。 (2)计算KH2PO4和等体积、等物质的量K。PO。混合液的pH。
【单选题】HPO 4 2- 的共轭碱是 -------( ) (A) H 2 PO 4- (B) H 3 PO 4 (C)PO 4 3- (D) OH -
【单选题】有关 H 3 PO 4 、 H 3 PO 3 及 H 3 PO 2 的论述错误的是
A.
它们可以分别用 (HO) 3 PO 、 (HO) 2 PHO 、 HOPH 2 O 代表
B.
它们的相对酸性 H 3 PO 4 > H 3 PO 3 > H 3 PO 2