25℃时,改变0.1mol·L
-1弱酸RCOOH溶液的pH,溶液中RCOOH分子的物质的量分数δ(RCOOH)随之改变[已知δ(RCOOH)=
![](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%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmtext%3ERCOOH%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmtext%3Ec%3C%2Fmtext%3E%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmtext%3ERCOOH%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3Cmtext%3E%2Bc%3C%2Fmtext%3E%3Cmrow%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmrow%3E%3Cmsup%3E%3Cmrow%3E%3Cmtext%3ERCOO%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmtext%3E-%3C%2Fmtext%3E%3C%2Fmsup%3E%3C%2Fmrow%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
],甲酸(HCOOH)与丙酸(CH
3CH
2COOH)溶液中δ(RCOOH)与pH的关系如图。下列说法正确的是( )
- A、pH=4的丙酸和甲酸溶液稀释100倍后对应溶液中的c(H+):甲酸>丙酸
- B、25℃时,等浓度甲酸与丙酸混合后,丙酸的电离平衡常数K>10-4.88
- C、浓度均为0.1mol·L-1的HCOONa和CH3CH2COONa的混合溶液中:c(H+)+c(CH3CH2COOH)+c(HCOOH)=c(OH-)+c(HCOO-)+c(CH3CH2COO-)
- D、将0.1mol·L-1的HCOOH溶液与0.1mol·L-1的HCOONa溶液等体积混合,所得溶液中:c(HCOO-)>c(Na+)>c(HCOOH)>c(H+)>c(OH-)