【单选题】NaOH 滴定 H3PO4 以酚酞为指示剂,终点时生成( )。(已知 H3PO4 的各级离解常数:Ka1=6.9×10^-3,Ka2=6.2×10^-8,Ka3=4.8×10^-13)
【单选题】化妆品等高档产品的软包装采用最好的材料是()
【简答题】已知H 3 PO 4 的 。H 3 PO 4 的共轭碱为______,其 值为______。
【单选题】What resulted from the crash?
A.
50 passengers were killed.
B.
The flight from Newark to Buffalo was canceled.
C.
Some flights to the Buffalo airport were delayed.
D.
12 houses near the crash site were ruined by fire.
【单选题】需要高温蒸煮及保存时间相对较长的药物、化妆品等高档产品的软包装采用最好的材料是
【单选题】需要高温蒸煮及保存时间相对较长的药物、化妆品等高档产品的软包装采用最好的材料是( )
【多选题】根据《基金会管理条例》,基金会理事会决议的下列事项中,须经出席理事表决且 2/3 以上通过方为有效的有( )。