Answer:
6.27 [gr].
Explanation:
the required mass can be calculated as:
m[Ca(OH)₂]=M[Ca(OH)₂]*m[CaCl₂]/M[CaCl₂], where M - molar mass [gr/mol], m - mass [gr];
m[Ca(OH)₂]=9.4*74/111≈6.2(6) [gr].
Chemical reaction (dissociation) 1: C₂O₄H₂(aq) ⇄ C₂O₄H⁻(aq) + H⁺(aq).
Chemical reaction (dissociation) 2: C₂O₄H⁻(aq) ⇄ C₂O₄²⁻(aq) + H⁺(aq).
c(C₂O₄H⁻) = c(H⁺) = x.
c(C₂O₄H₂) = 0.0269 M.
pKa₁ = 1.23.
Ka₁ = 10∧(-1.23) = 0.059.
Ka₁ = c(C₂O₄H⁻) · c(H⁺) / c(C₂O₄H₂).
0.059 = x² / (0.0269 M - x).
Solve quadratic eqaution: x = c(H⁺) = 0.02 M.
pH = -log(0.02 M) = 1.7.
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Answer:
She should take one
Explanation:
because it is the closest option to 1.04 and if you dont have the right dosage then you always want to take the smaller dose as opose to a bigger dose
