CH3COONa已知浓度、电离平衡常数求pH,水解度
来源:学生作业帮 编辑:作业帮 分类:化学作业 时间:2024/10/04 16:09:33
CH3COONa已知浓度、电离平衡常数求pH,水解度
CH3COONa浓度为0.1mol/L
CH3COOH电离平衡常数k为1.8*10^-5
求pH值,水解度
CH3COONa浓度为0.1mol/L
CH3COOH电离平衡常数k为1.8*10^-5
求pH值,水解度
设:水解平衡时的[OH-]为y (mol/L)
Ac- + H2O = HAc + OH-
平衡时:c-y y y
K = [HAc] × [OH-] ÷[Ac-]
= ([HAc] × [OH-] × [H+] )÷ ([Ac-] × [H+])
= Kw ÷ Ka
K= Kw ÷ Ka = 1.0*10^-14 ÷ 1.8*10^-5 = 5.56*10^-10
∵[HAc] × [OH-] ÷[Ac-] = y^2 / ( c-y) = K (∵ (c-y) ≈ c )
∴ y = √ ( c × K)
= √ (0.1*5.56*10^-10) = 7.45*10^-6 (mol/L)
POH= -Lg(7.45*10^-6)=5.13
因此:PH = 14 - 5.13 = 8.87
水解度=y ÷ c*100% = 7.45*10^-6 ÷0.1 × 100% = 0.00745%
Ac- + H2O = HAc + OH-
平衡时:c-y y y
K = [HAc] × [OH-] ÷[Ac-]
= ([HAc] × [OH-] × [H+] )÷ ([Ac-] × [H+])
= Kw ÷ Ka
K= Kw ÷ Ka = 1.0*10^-14 ÷ 1.8*10^-5 = 5.56*10^-10
∵[HAc] × [OH-] ÷[Ac-] = y^2 / ( c-y) = K (∵ (c-y) ≈ c )
∴ y = √ ( c × K)
= √ (0.1*5.56*10^-10) = 7.45*10^-6 (mol/L)
POH= -Lg(7.45*10^-6)=5.13
因此:PH = 14 - 5.13 = 8.87
水解度=y ÷ c*100% = 7.45*10^-6 ÷0.1 × 100% = 0.00745%
CH3COONa已知浓度、电离平衡常数求pH,水解度
CH3COONa水解后电离
水解平衡常数与其电离平衡常数的关系
电离平衡常数和水解平衡常数的关系
已知电离常数和浓度,怎么求PH值
浓度不影响电离平衡常数
等体积氨水与盐酸混合,使PH=7,则铵根离子浓度与氯离子浓度谁大,电离平衡常数怎么求?
ph=10的ch3coona中水电离的h+浓度是10∧(-10)对吗
CH3COONa水解,若增加盐的浓度,PH值如何变,为什么
醋酸已知pH为2.8,浓度为0.05mol/l.电离常数Ka与电离度a怎么求.(这是实验)
已知HSO4-的解离平衡常数为0.01,求0.01mol/L的H2SO4中H+浓度和pH.
怎样根据电离平衡常数判断PH