19.(单选题)已知HF的Ka = 6.30×10-4,C6H5OH的Ka = 1. 0×10-10,由此可知HF与C6H5OH相比,其酸性( )(本题1.0分)
A.HF比C6H5OH强
B.HF比C6H5OH弱
C.HF与C6H5OH酸性相等
D.HF比C6H5O-碱性强
E.无法比较

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