【单选题】已知常温下 H 3 PO 4 的 p K a1 = 2.12 , p K a2 = 7.21 , p K a3 = 12.66 下列缓冲对中,最适合于配制 pH 为 2.0 的缓冲溶液的是 ( )
【判断题】mil机构域名的意思是非军事性政府或组织
【单选题】若向一定浓度的 NaH 2 PO 4 溶液中加入 NaOH 固体配制 pH 为 7.21 且与血液等渗的缓冲溶液(假设溶液体积不变 ), 则原 NaH 2 PO 4 溶液的浓度应为 ( 已知常温下 H 3 PO 4 的 p K a1 =2.16,p K a2 =7.21,p K a3 =12.32)
【单选题】The best title of the passage is ______.
A.
The Structure of an Essay
B.
How to Write the Body of the Thesis
C.
How to Write the Structure of the Essay
D.
The Opening Paragraph and the Conclusion
【单选题】若用相同浓度的 H 3 PO 4 溶液 ( 已知常温下 H 3 PO 4 的 p K a1 =2.16, p K a2 =7.21, p K a 3 =12.32) 和 NaOH 溶液配制 pH=7.21 的缓冲溶液 , 则 H 3 PO 4 溶液和 NaOH 溶液的体积比应为
【简答题】Read the following passage. Complete the diagram by using the information for the passage. Write NO MORE THAN 3 WORDS for each answer. Since it was founded a year ago, the babysitting pool has become ...
【简答题】Write an essay of no less than 160 words in response to the prompt below.Write the passage on the answer sheet. “Books are the quietest and most constant of friends;they are the most accessible and wi...