Respuesta :
pH=-lg[H⁺]
pH=-lg(2.8×10⁻⁹)=8.553
pOH=14-pH
pOH=14-8.553=5.447
[OH⁻]=10^(-pOH)
[OH⁻]=10⁻⁵·⁴⁴⁷=3.6×10⁻⁶
pH=-lg(2.8×10⁻⁹)=8.553
pOH=14-pH
pOH=14-8.553=5.447
[OH⁻]=10^(-pOH)
[OH⁻]=10⁻⁵·⁴⁴⁷=3.6×10⁻⁶
Answer: The correct answer is [tex]3.6\times 10^{-6}[/tex]
Explanation:
We are given:
Acid dissociation constant [tex](k_a)=2.8\times 10^{-9}[/tex]
Water dissociation constant [tex](k_w)=1\times 10^{-14}[/tex]
To calculate the base dissociation constant for the conjugate base, we use the equation:
[tex]k_w=k_a\times k_b[/tex]
where,
[tex]k_b[/tex] = base dissociation constant
Putting values in above equation, we get:
[tex]10^{-14}=2.8\times 10^-9}\times k_b\\\\k_b=3.6\times 10^{-6}[/tex]
Hence, the correct answer is [tex]3.6\times 10^{-6}[/tex]
