次磷酸(H
3PO
2)是一种精细磷化工产品。常温下,某实验小组以酚酞为指示剂,用0.100 mol·L
-1的NaOH溶液滴定20.00 mL未知浓度的次磷酸(H
3PO
2)溶液。溶液pH、所有含磷微粒的分布系数δ随滴加NaOH溶液体积V(NaOH)的变化关系如图所示。[比如H
2PO
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsubsup%3E%3Cmrow%3E%3C%2Fmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmtext%3E-%3C%2Fmtext%3E%3C%2Fmsubsup%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的分布系数:δ(H
2PO
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsubsup%3E%3Cmrow%3E%3C%2Fmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmtext%3E-%3C%2Fmtext%3E%3C%2Fmsubsup%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
)=
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmfrac%3E%3Cmrow%3E%3Cmtext%3Ec%3C%2Fmtext%3E%3Cmo+stretchy%3D%22false%22%3E%28%3C%2Fmo%3E%3Cmsub%3E%3Cmtext%3EH%3C%2Fmtext%3E%3Cmtext%3E2%3C%2Fmtext%3E%3C%2Fmsub%3E%3Cmsubsup%3E%3Cmrow%3E%3Cmtext%3EPO%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmtext%3E-%3C%2Fmtext%3E%3C%2Fmsubsup%3E%3Cmo+stretchy%3D%22false%22%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmtext%3Ec%3C%2Fmtext%3E%3Cmo+stretchy%3D%22false%22%3E%28%3C%2Fmo%3E%3Cmi%3E%E6%80%BB%3C%2Fmi%3E%3Cmi%3E%E5%90%AB%3C%2Fmi%3E%3Cmi%3E%E7%A3%B7%3C%2Fmi%3E%3Cmi%3E%E5%BE%AE%3C%2Fmi%3E%3Cmi%3E%E7%B2%92%3C%2Fmi%3E%3Cmo+stretchy%3D%22false%22%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
],下列叙述正确的是( )
- A、曲线①代表δ(H2PO
),曲线②代表δ(HPO
) - B、H3PO2溶液的浓度为0.100 mol·L-1
- C、H2PO
水解常数Kh≈1.0×10-10 - D、NaH2PO2是酸式盐,其水溶液显碱性