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【单选题】
已知H 3 PO 4 的 , , 。预配制pH=7.0的缓冲溶液,可选择的缓冲对是:A.
H 3 PO 4 - NaH 2 PO 4
B.
NaH 2 PO 4 -Na 2 HPO 4
C.
Na 2 HPO 4 -Na 3 PO 4
D.
纯水
E.
H 3 PO 4 -Na 3 PO 4
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