Answer is: ph value is 3.56.
Chemical reaction 1: H₂CO₃(aq) ⇄ HCO₃⁻(aq) + H⁺(aq); Ka₁ = 4,3·10⁻⁷.
Chemical reaction 2: HCO₃⁻(aq) ⇄ CO₃²⁻(aq) + H⁺(aq); Ka₂ = 5,6·10⁻¹¹.
c(H₂CO₃) = 0,18 M.
[HCO₃⁻] = [H⁺<span>] = x.
</span>[H₂CO₃] = 0,18 M - x.
Ka₁ = [HCO₃⁻] · [H⁺] / [H₂CO₃].
4,3·10⁻⁷ = x² / (0,18 M -x).
Solve quadratic equation: x = [H⁺] =0,000293 M.
pH = -log[H⁺] = -log(0,000293 M).
pH = 3,56; second Ka do not contributes pH value a lot.
Answer:
Magnesium Difluoride
Explanation:
Mg = magnesium
F = fluoride
F2 = difluoride (prefix "di" indicates 2)
is this a cult?im confused
Answer:
X(Cl-35) = 75.95% => Answer 'A'
Explanation:
34.9689·X(Cl-35) + 36.9695·X(Cl-37) = 35.45; X = fractional abundance
X(Cl-35) + X(Cl-37) = 1 ⇒ X(Cl-37) = 1 - X(Cl-25)
34.9689·X(Cl-35) + 36.9695(1 - X(Cl-35)) = 35.45
34.9689·X(Cl-35) + 36.9695 - 36.9695·X(Cl-35) = 35.45
Rearrange ...
36.9695·X(Cl-35) - 34.9689·X(Cl-35) = 36.9689 - 35.45
2.0006·X(Cl-35) = 1.5195
X(Cl-35) = 1.5195/2.0006 = 0.7595 fractional abundance
⇒ % abundance = 75.95%
