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2017-11-16 12:06 am

A 25 ml sample of well water for chloride determination requires 34.32 ml of 0.05012 M AgNO3 solution to reach a sodium chromate endpoint. Calculate the concentration of chloride ion in the water sample.

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戇戇居士

2017-11-16 12:56 am

✔ 最佳答案

EquaEquation for the reaction :
Ag⁺(aq) + Cl⁻(aq) → AgCl(s) …… (Na₂CrO₄ as indicator)
Mole ratio AgNO₃ : Cl⁻ = Ag⁺ : Cl⁻ = 1 : 1

No. of milli-moles of AgNO₃ = (0.05012 mmol/ml) × (34.32 ml) = 1.720 mmol
No. of milli-moles of Cl⁻ = 1.720 mmol
Concentration of Cl⁻ ion = (1.720 mmol) / (25 ml) = 0.0688 M
tion for the reaction :
Ag⁺(aq) + Cl⁻(aq) → AgCl(s) …… (Na₂CrO₄ as indicator)
Mole ratio AgNO₃ : Cl⁻ = Ag⁺ : Cl⁻ = 1 : 1

No. of milli-moles of AgNO₃ = (0.05012 mmol/ml) × (34.32 ml) = 1.720 mmol
No. of milli-moles of Cl⁻ = 1.720 mmol
Concentration of Cl⁻ ion = (1.720 mmol) / (25 ml) = 0.0688 M

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