Answer:
[H⁺] = 10⁻¹²
It could be the strongest base.
Explanation:
The base is considered to be of highest strength if it has least hydrogen ion concentration or high hydroxide ion concentration.
Generally a stronger base gives more hydroxide ion concentration.
the relation between hydrogen ion and hydroxide ion concentration is
[H⁺][OH⁻]= 10⁻¹⁴
[OH⁻] = 10⁻¹⁴ / [H⁺]
a) [H⁺] = 10⁻⁹
[OH-] = 10⁻⁵
b) [H⁺] = 10⁻¹¹
[OH-] = 10⁻³
c) [H⁺] = 10⁻¹⁰
[OH-] = 10⁻⁴
d) [H⁺] = 10⁻¹²
[OH-] = 10⁻²
This the highest concentration of hydroxide ion in the given choices so it could be the strongest base.
B. product
Answer:
pH=8.32
Explanation:
The relevant equilibrium for this problem is
F⁻ + H₂O ↔ HF + OH⁻
With a constant Kb of
Kb=
Kb=
To calculate the value of Kb we use the formula Kw=Ka*Kb, where Kw is the ionization constant of water, 1 * 10⁻¹⁴.
1 * 10⁻¹⁴ = 7.2*10⁻⁴ * Kb
Kb = 1.4 * 10⁻¹¹
So now we have
1.4 * 10⁻¹¹=
We make the assumption that x<<<0.30 M, so we can rewrite the equation of Kb as:
1.4 * 10⁻¹¹=
So [OH⁻]=2.05*10⁻⁶