Answer:
3.51
Explanation:
Before any sodium hydroxide has been added, the pH is that of the aqueous hydrofluoric acid solution.
HF is a weak acid that dissociates according to the following equation.
HF(aq) ⇄ H⁺(aq) + F⁻(aq) Ka = 6.76 × 10⁻⁴
We can find [H⁺] using the following expression.
[H⁺] = √(Ca × Ka)
where
Ca: concentration of the acid
Ka: acid dissociation constant
[H⁺] = √(Ca × Ka)
[H⁺] = √(0.458 × 6.76 × 10⁻⁴)
[H⁺] = 3.10 × 10⁻⁴ M
The pH is:
pH = -log [H⁺]
pH = -log 3.10 × 10⁻⁴ = 3.51
Answer: the number of circles in the electronic configuration of an element is represented in the periodic table as the period number that element is situated in. the number of electrons in the outermost shell of an element is represented in the periodic table as the group number that element is situated in.
Explanation: hope it helps :)
I think it is 3 because Sus wiw word if rn
