zinc czn be determined volumetrically by d precipitation reaction

3Zn^+2 + 2[4K+,Fe(CN)6^4+] ->K2Zn3[Fe(CN)6]2 + 6k+

A sample of zinc ore weighing 1.5432g was prepared for reaction & required 34.68ml of 0.1043 M K4Fe(CN)6 FOR tritation.Calculate d % of zn in d ore..

To determine the percentage of zinc in the ore sample using the given precipitation reaction, we need to follow a series of steps involving stoichiometry and molarity calculations. Let's break this down step by step.

Understanding the Reaction

The reaction provided is:

3Zn²⁺ + 2[K⁺, Fe(CN)₆^4-] → K₂Zn₃[Fe(CN)₆]₂ + 6K⁺

This indicates that 3 moles of zinc ions react with 2 moles of potassium ferrocyanide. This stoichiometry will be crucial for our calculations.

Calculating Moles of K₄Fe(CN)₆

First, we need to calculate the number of moles of potassium ferrocyanide used in the titration. The formula for calculating moles is:

Moles = Molarity × Volume (in liters)

Given that the molarity of K₄Fe(CN)₆ is 0.1043 M and the volume used is 34.68 mL, we convert the volume to liters:

• 34.68 mL = 34.68 / 1000 = 0.03468 L

Now, we can calculate the moles:

Moles of K₄Fe(CN)₆ = 0.1043 M × 0.03468 L = 0.00362 moles

Using Stoichiometry to Find Moles of Zn

From the balanced equation, we see that 2 moles of K₄Fe(CN)₆ react with 3 moles of Zn²⁺. Therefore, we can set up a ratio to find the moles of zinc:

2 moles K₄Fe(CN)₆ : 3 moles Zn

Using the moles of K₄Fe(CN)₆ calculated:

Moles of Zn = (3/2) × Moles of K₄Fe(CN)₆ = (3/2) × 0.00362 = 0.00543 moles

Calculating Mass of Zinc

Next, we need to convert the moles of zinc to grams. The molar mass of zinc (Zn) is approximately 65.38 g/mol. Thus:

Mass of Zn = Moles of Zn × Molar Mass of Zn

Mass of Zn = 0.00543 moles × 65.38 g/mol = 0.355 g

Finding the Percentage of Zinc in the Ore

Finally, to find the percentage of zinc in the original ore sample, we use the formula:

Percentage of Zn = (Mass of Zn / Mass of Ore) × 100%

Substituting the values we have:

Percentage of Zn = (0.355 g / 1.5432 g) × 100% ≈ 23.0%

Final Result

Therefore, the percentage of zinc in the ore sample is approximately 23.0%.